bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations of molar morphology in the Spalax ehrenbergi superspecies: adaptive and phylogenetic significance
Authors: Butler P. M. , Nevo E. , Beiles A. , Simson S.
Published: March 2009

This study compares and contrasts variations of enamel fold pattern on the crowns of the molars of subterranean mole rats (Spalax) belonging to two superspecies, S. ehrenbergi and S. leucodon, and involving about 20 chromosomal species, distributed parapatrically and ranging on different soil types. The sample studied involved 397 skulls, subdivided as follows: 280 of S. ehrenbergi from Israel, representing the four chromosomal species 2n = 52, 54, 58 and 60; 59 of S. ehrenbergi from Egypt, Lebanon, Syria, Jordan and Turkey; 58 of S. leucodon from Turkey.

In making the comparisons it was necessary to take into account the marked changes of molar pattern that take place as a result of wear.

There is a reasonably good agreement between differences of molar pattern and genetic and immunological distances. The species in Israel and Egypt form a compact group, clearly differentiated from Turkish leucodon; ehrenbergi from Turkey and Syria are intermediate, in accordance with their geographical distribution.

In Israel, differences associated with soil type are at about the same level as differences between species. Local populations show a higher level of diversity, and in a number of cases neighbouring populations differed significantly, sometimes over very short distances. Population differences within species are generally associated with differences of soil and vegetation, indicating the influence of natural selection. There are also differences across species boundaries, implying a phylogenetic (heritage) effect. The nature of the adaptive link between molar pattern and soil is unknown: possible factors are contamination of the food by soil, and toughness of the food which necessitates changes of enamel fold length to improve grinding efficiency.
Structural modifications involved in the fore‐ and hind limb grip of some flying foxes (Chiroptera: Pteropodidae)
Authors: Bennett M. B.
Published: March 2009

A mechanism which enables flying foxes to lock their hind limb digits and thumbs in flexion is described. The deep digital tendons of the hind limbs have roughened fibrocartilage surfaces. The adjacent flexor tendon sheath supports ridges which interact with the rough tendon surface, temporarily ‘locking’ the two structures together. This tendon locking mechanism is of importance as it enables bats to reduce the energetic cost of hanging from branches. It does this by reducing, or eliminating, the need for digital flexor muscle activity.
Spatial and temporal ecology of an assemblage of viverrids in Natal, South Africa
Authors: Maddock A. H. , Perrin M. R.
Published: March 2009

Aspects of community structure and organization are examined in an assemblage offive species of small carnivores (Family Viverridae). Comparative use of the spatial and temporal niches for each species is studied and used to interpret coexistence. The spatial niche segregates the assemblage into three groups, including a three‐species mixed‐forest group. This mixed‐forest group comprises a single‐species diurnal branch and a nocturnal branch. Segregation of the nocturnal branch may only be achieved through trophic differences.
Are geckos olfactory specialists?
Authors: Schwenk Kurt
Published: March 2009

Gekkonid lizards are shown to have well‐developed nasal chemical senses. It is argued that they are unique among squamates so far studied in the degree of their olfactory (as opposed to vomeronasal) development. This contention is supported by evidence from the brain, nasal capsule, tongue, and experimental studies of behaviour. Limited evidence suggests that olfaction functions in food‐finding and predator detection; vomerolfaction during investigation of novel stimuli and in reproduction. The conception of gekkonids as members of a ‘visual Ascalabota’ is not supported by these findings. Olfactory specialization makes geckos ideal subjects for tests of the Cowles and Phelan hypothesis of olfactory function and suggests that they might be better subjects than snakes for future studies of dual olfactory form, function and evolution in a nonmammalian lineage.
Post‐natal growth of elephantsLoxodonta africanain Etosha National Park, Namibia
Authors: Lindeque M. , Jaarsveld A. S. van
Published: March 2009

Post‐natal growth in the African elephant (Loxodonta africana) was described using three alternative mathematical models, and two age estimation schedules. Von Bertalanffy, Gompertz and Logistic equations all provided adequate models of post‐natal growth in a species for which age estimation methods are largely unsubstantiated. Gompertz and Logistic models overestimated pre‐weaning growth and underestimated adult size. Self‐accelerating growth is of short duration (one and three years in females and males, respectively), and we found no evidence of a secondary growth spurt in males. Males, nevertheless, continue to grow throughout their lifespan, while females reach asymptotic size at the age of 35–40 years. We found no evidence of differences in growth rate of males and females up to 10 years, and there does not seem to be differential investment in male and female offspring. Growth rates of captive elephants differ substantially from all wild populations studied and may not serve as adequate references for the revision of existing age estimation schedules.
Anti‐predator defences of a web‐building spider, Holocnemus pluchei (Araneae, Pholcidae)
Authors: Jackson R. R. , Jakob E. M. , Willey M. B. , Campbell G. E.
Published: March 2009

Anti‐predator defence behaviour of Holocnemus pluchei (Araneae, Pholcidae) was studied in the laboratory and the field. Bouncing, in which this web‐building spider moves its body rapidly up and down while keeping its legs on the silk, was the most frequent response to disturbance. Less often, H. pluchei left the web when disturbed. Experiments were carried out to determine the types of stimuli that elicited bouncing and leaving the web: tactile stimulation (striking the spider with a brush) and air movement (blowing on the spider) elicited bouncing and leaving the web, but there was no evidence that chemical stimuli from potential predators were important. Tactile stimulation elicited stronger responses than air movement. There were no evident differences in how H. pluchei responded to tactile stimulation in the laboratory and the field.
Histoircal changes in the ecology and behaviour of semaphore geckos (Pristurus, Gekkonidae) and their relatives
Authors: Arnold E. N.
Published: March 2009

Semaphore geckos (Pristurus) and thier relatives have a very robust and explicit morphological phylogeny, consisting of a long pectinate tree in which the number of derived morphological states increases steadily through time. This clade consequently provides a firm base for investingating changes in ecology and behaviour. Data on these topics including diet, pattern of tail shedding and clutch size were integrated with the phylogeny and substantial regularity demonstrated in the way they have changed over time. Ancestral forms were apparently climbers on rocky surfaces and active in subdued light. There was subsequent shift into more open, sunny situations with two or three transfers into arboreal habitats which were accompanied by reversion to more shaded conditions. A change to ground‐dwelling occurred perhaps twice within Pristurus, including the ancestor of the Spatalura clade, a group which has reverted to typical gecko nocturnality while still retaining diurnal activity. Overall, there has been a progression into hotter, drier and more open habitats.

Other shifts within the clade are adoption of passive foraging techniques, development and elaboration of intraspecific tail signalling and change in the kinds of refuges used. Clutch size fell from two eggs to one early in the clade history with subseqauent partial reversion to two. Ants and sometimes termites became an importnt item of diet in some taxa and frequent trombiculid mite infestation appeared in the terminal group within which caudal autotomy became confined to the tail base.

Overall, the habitats occupied by morphologically advanced Pristurus, appear more demanding, and perhaps less rewarding, than those in which their more primitive relatives live. This may result from species that did less well in competition, following each of the speciation events on the main stem of the phylogeny, being dispolaced into increasingly severe niches. The substantial morphological changes taking place in the evolution of the clade may be related to the problems of survival in these.
New methods of tooth microwear analysis and application to dietary determination of two extinct antelopes
Authors: Solounias N. , Hayek Lee‐Ann C.
Published: March 2009

A separation exists between the tooth microwear of extant ruminant browsers and grazers when examined with new statistical techniques such as the dichotomous, polychotomous and continuous methods. Extant mixed feeders, however, could not be discerned as a distinct group. Many variables were used in the analysis, including two new variables; the area and perimeter of scars.A standard definition of a pit is deduced and a recommendation is made for a method and a model which best charactrizes the enamel scars for determination of browsing and grazing dietary categories. The best diagnostic method of tooth microwear analysis utilizes the number of pits smaller than or equal to the ratio four (lenth over width), the number of scratches between four and 100 micrometres in length to width ratio, and the number of gouges greater than 100 micrometres in length to width ratio. Browsers have many pits and few scratches, with the exception of the giraffe. Grazers have many scratches and few pits, with the exception of the common waterbuck.

The tooth microwear analysis suggests that Tragoportax amalthea (Boselaphini, Bovidae) was a mixed feeder at Pikermi and a grazer at Samos. Using the dietary adaptations and the time differences (Pikermi is slightly older than Samos), it is assumed that we ahve recorded evolutionary change from a mixed feeder to a grazer. Tragoportax rugosifrons from Samos was a grazer. Pikermi and Samos are Miocene (Turolian) localities in Greece.
Dichromatism in relation to the trophic biology of predatory cichlid fishes in Lake Tanganyika, East Africa
Authors: Kohda Masanori , Hori Michio
Published: March 2009

A population of the piscivorous Tanganyikan cichlid,Lepidiolamprologus profundicolacontains individually distinct pale and dark colour morphs: a dichromatism not related to age or sex. The ‘dark form’ frequently targets prey from the shaded space under rocks, while the ‘plae form’ targets prey in well‐iluminated open water. This hunting site specialization is not ascribable to the differences of microhabitat that the predators of each form encounter. The main function of the dichromatism is apparently cryptic, as a camouflage for hunting. Interspecific comparisons among 19 species of carnivorous Tanganyikan cichlid fishes reveal that dichromatic taxa generally chase an active prey: fishes, scales of fishes or highly mobile free‐swimming crustacea. In contrast, cichlid species foraging on a sessile or sluggish prey are monochromatic. This finding strongly supports the hypothesis that a pale‐dark dichromatism serves to optimize foraging efficiency in predatory cichlids hunting an active prey.
Social organization and mating system of the plains viscacha (Lagostomus maximus)1
Authors: Branch Lyn C.
Published: March 2009

Plains viscachas live in communal burrow systems in groups containing one or more males, several females and immatures. Viscachas forage in groups at night and aggregate underground during the day. All members of a group use burrows throughout the communual burrow system and participate in digging at the burrows. Alarm calls are given primarily by adult males. Allogrooming occurs among all sex‐age classes within a social group but not between members of different social groups. Agonistic interactions occur more often between members of different social groups than within a group.

The long‐term social unit of the plains viscacha is the female group. Resident males disappear each year and new males join groups of females. Dominance is absent among females. Agonistic interactions are rare among adult males within a social group and dominance is not clearly evident.
Penial differentiation in speciation of subterranean mole rats Spalax ehrenbergi in Israel
Authors: Simson S. , Lavie B. , Nevo E.
Published: March 2009

Geographic and ontogenetic variation was examined in the glans penes and bacula of 92 specimens representing four biological species with the karyotypes 2n=52, 54, 58 and 60 of the Spalax ehrenbergi superspecies in 13 populations from Israel and one disjunct population from northern Egypt. Five measured and three calculated penial characters were analysed and employed in multivariate statistics. Comparison was made between penial morphological characters and craniometric biochemical and chromosomal data. The baculum is strongly species‐specific and its length bears no significant relationships with head and body length. The results of these analyses suggest that different bacular morphologies may provide a basis for species‐specific prezygotic isolating mechanisms, thus, together with other factors, contributing to reproductive isolation and speciation.
Splenic respiratory compensation and blood volume in the newt
Authors: Frangioni G. , Borgioli G.
Published: March 2009

In the newt Triturus cristatus carnifex, reversible increase in size of the spleen is linked to the respiratory state of the animal: when the newt is exposed to the air, and thus well oxygenated, the spleen hoards erythrocytes; when immersed in still water, in an hypoxic state, the spleen releases erythrocytes into the bloodstream. In chlorobutanol‐anaesthetized specimens exposed to the air, the maximum size reached by the spleen diminishes with a rise in temperature up to the disappearance of all congestion at 33°C. The blood volume of newts kept in humid air at 6°C and 18°C after anaesthesia varies from about 6–9 ml per 100 g of body weight, while the red blood cell count and haematocrit value remain stable. In anaesthetized specimens kept in still water at the same temperatures the blood volume is stable, at about 7 ml per 100 g, but the red cell count and haematocrit are notably higher. At 33°C, a critical temperature for the newts, the specimens in still water succumb while those in air present the same blood volume as at 18°C, but have a higher erythrocyte count and haematocrit value.
Sympatric populations of muntjac (Muntiacus reevesi) and roe deer (Capreolus capreolus): a comparative analysis of their ranging behaviour, social organization and activity
Authors: Chapman Norma G. , Claydon Kathie , Claydon M. , Forde P. G. , Harris S.
Published: March 2009

The ranging behaviour, activity and social organization of sympatric populations of Reeves' muntjac (Muntiacus reevesi) and roe deer (Capreolus capreolus) in a mainly commercial coniferous forest in eastern England were studied by means of radio‐tracking techniques. Muntjac showed no seasonal changes in range size; muntjac bucks had significantly larger ranges than does at all times of the year. For roe deer there were significant seasonal changes in home‐range size; bucks had largest ranges in the winter months and smallest ranges in September‐October, whereas does had largest ranges during January‐February and minimum ranges during May‐June. There was no seasonal change in the number or size of muntjac core areas; bucks always had larger and more numerous core areas than does. Neither was there a seasonal change in the number or size of roe deer core areas; whilst there was no difference in the number of core areas for roe bucks and does, those of bucks were significantly smaller. There was no seasonal change in daily distance travelled by muntjac bucks or does, or roe bucks, but there was a significant seasonal trend for roe does, whose daily distances travelled were longest during January‐February and shortest during May‐June.

Spatial organization of muntjac consisted of groups of overlapping doe ranges but exclusive back ranges; these overlapped with one or more groups of doe ranges. During the summer, roe deer buck and doe ranges overlapped, and some doe ranges were shared with other adult does, but buck ranges were exclusive. During the winter, roe deer were more wide‐ranging and mixed more freely. There was no evidence for spatial separation of muntjac and roe deer; minimum convex polygon ranges overlapped and core areas often coincided. Mean annual activity was 69.3 ± 1.5% for muntjac and 56.4 ± 1.8% for roe deer. Mean length of active periods was significantly greater for muntjac than roe deer, and roe deer had significantly longer inactive periods. For muntjac there were peaks of activity at dusk and dawn, with lower levels of activity during the day and night. For roe deer the dawn and dusk peaks were more clearly defined, and at most times of the year nocturnal activity was higher than diurnal activity.

These results are discussed in relation to the physiology of the two species and their patterns of space and food utilization, and the evidence for resource partitioning between the two species is evaluated. It was shown that neither muntjac nor roe deer had an effect on the ranging behaviour, activity and social organization of the other species, but that at very high densities muntjac can have an impact on established roe deer populations by changing their pattern of habitat utilization and by locally reducing their numbers.
The relationship between nectar supply and the rate of capture of a nectar‐dependent small marsupial Tarsipes rostratus
Authors: Wooller R. D. , Richardson K. C. , Collins B. G.
Published: March 2009

The shrew‐sized marsupial Tarsipes rostratus, endemic to south‐western Australia, eats only nectar and pollen. Tarsipes were caught at four sites, each with 100 pitfall traps, during 21 threeday periods over three years. On these occasions, the numbers of adult females, all adults and all Tarsipes caught were each significantly related to the estimated nectar production of the plants most frequently visited by Tarsipes. Sites with higher levels of nectar production had higher capture rates in each of the three years. Changes in the population density of the short‐lived ( 1 year) Tarsipes appeared directly related to changes in nectar levels through differential survival, rather than by migration or fecundity.
Ingestion and assimilation of leaf litter in some tropical millipedes
Authors: Dangerfield J. M. , Milner Alice E.
Published: March 2009

Ingestion and assimilation rates in six species of tropical millipede (Diplopoda: Spirostreptidae) from southern Africa are estimated for the first time and were found to vary both within and between species. A proportion of this variability was attributable to variation in body size effects as individuals ranged from 0.2 to 2.9 g dry mass. Mean ingestion rates for each species were 17,30, 34.32 and 75 mg dry leaf litter per day (7.6 to 2.6% of body mass). Within species, ingestion rates explained between 35 and 53% of the variation in assimilation. Large size did not necessarily enhance assimilation efficiencies, which were between 7 and 26%) and comparable to assimilation efficiencies reported for temperate species, but did result in greater absolute ingestion and assimilation of organic material per individual.
Retarded senescence in an insular population of Virginia opossums (Didelphis virginiana)
Authors: Austad Steven N.
Published: March 2009

Evolutionary senescence theory predicts that genetically isolated populations historically subjected to low rates of environmentally‐imposed mortality will ultimately evolve senescence that is retarded in relation to that of populations historically subjected to higher mortality rates. This prediction was evaluated in the field by comparing three general measures of senescence—age‐specific mortality rate acceleration, age‐related reproductive output and tail tendon collagen denaturation rate—in two radiocollared Virginia opossum (Didelphis virginiana) populations, one a mainland control and the other an insular population having a four‐to five‐thousand‐year history of reduced exposure to predators. In comparison with those on the mainland, insular female opossums were found to exhibit greater survivorship and reduced litter sizes at all ages, as well as slower acceleration of age‐specific mortality. Also, island females in their second reproductive year failed to show the senescent reduction in pouch young growth rate seen in mainland animals. Island opossums also manifested slower ‘ageing’ of tail tendon fibres, a generalized measure of physiological ageing. All these results are consistent with evolutionary senescence theory. Various environmental explanations (parasitism, disease, lessened food availability) for this populational difference are evaluated by physiological measures. No evidence for an environmental explanation is found.
Use of prey‐specific predatory behaviour by North American jumping spiders (Araneae, Salticidae) of the genus Phidippus
Authors: Edwards G. B. , Jackson R. R.
Published: March 2009

Prey‐capture behaviour of seven species of Phidippus is studied using two types of prey, house flies (adult Musca domestica) and caterpillars (cabbage loopers, larval Trichoplusia ni). Each species is shown to be a versatile predator which uses a different prey‐specific prey‐capture behaviour depending on whether prey is a fly or a caterpillar: spiders approached the two types of prey differently and leapt on them from different distances. Interspecific differences among Phidippus species are not pronounced, cxcept for variation in the distance from which spiders jumped and the spider's success at capturing a fly on the first try.
Foraging ecology in the lizard Anolis oculatus (Iguanidae) from Dominica, West Indies
Authors: Bullock D. J. , Jury H. M. , Evans P. G. H.
Published: March 2009

In general, populations of Anolis lizards on West Indian islands face few predators, are at high density and are thought to be limited by food. This paper describes how the foraging ecology of Anolis oculatus, a solitary species confined to the island of Dominica, Lesser Antilles, varies with habitat and season in relation to the quantity and quality of available food.

Availability of invertebrate food (determined using pitfall traps and sticky traps) was greater in a dry scrub woodland site, Cabrits National Park (CNP), compared with a montane rainforest site, Palmiste Ridge. In the former, there were general increases in abundance, volumes of softbodied prey and sizes of invertebrates from dry season to wet season. Concomitant dietary changes, as determined principally by stomach flushing, included an increase (by volume) in the proportion of soft‐bodied prey. Dietary analyses confirmed the importance of ants (Formicidae) in the diet of A. oculatus, although for large individuals (mainly adult males) at the rainforest site, soft‐bodied prey such as Oligochaeta and Orthoptera were, in volumetric terms, more important. Prey capture observations showed that large A. oculatus fed mainly above ground. Anolis oculatus at the montane rainforest site used higher perch heights than those in dry scrub woodland, although in both habitats, small individuals (mainly juveniles) fed mainly at ground level on ants. In the dry season in CNP, the diet (in volumetric terms) of smaller Anolis was dominated by hardbodied prey such as ants, springtails (Collembola), barklice (Psocoptera) and beetles (Coleoptera). large Anolis used springtails and barklice to a lesser extent, resulting in relatively low food niche overlap values between size classes and a reduced potential for intraspecific competition compared with the wet season.
Feeding and gut contents in Cephalodiscus nigrescens (Hemichordata, Pterobranchia) from the Weddell Sea
Authors: Dilly P. N.
Published: March 2009

The gut of the pterobranch hemichordate Cephalodiscus nigrescens contains plankton of sizes from less than 1 μm to over 100 μm in diameter. Some of the smaller plankton are clumped together in spherical bolus that is mucus‐bound. Most plankton types known from the habitat are respresnted amongst the gut contents.
Foraging behaviour of dormice Muscardinus avellanarius in two contrasting habitats.
Authors: Bright P. W. , Morris P. A.
Published: March 2009

Anatomical evidence suggests that the dormourse is a specialist feeder. Radio‐tracking and direct observation confirm this, highly selective, arboreal feeding behaviour. Dormice choose flowers and fruits from a series of trees and shrubs as each becomes seasonally available. Deferred breeding and a high incidence of diurnal torper suggest that dormice experience food shortage in spring. In early summer, when flowering has ended, but fruits are not yet ripe, dormice may again suffer food shortage. At this time they appear to supplement their diet by taking insects, another high‐quality food with cyclic availability. Although some tree species are particularly valuable to dormice, they may not be essential if alternatives exist. A spectrum of species which will ensure a continuum of differeing food supplies, within a small area, is essential. This im;plies a need for heterogeneous woodland structure. The implications for conversation management are discussed.
Effects of food availability and intra‐and interspecific interaction on the dispersal tendency in the land snail Chondrina clienta
Authors: Baur Anette
Published: March 2009

The land snails Chondrina clienta and Baleaperversa compete most probably for a limited food resource (calcicolous lichens) on rock‐faces on the Baltic Island of Öland (Sweden). Two laboratory and three field experiments were conducted to determine whether food availability and intra‐ and interspecific interactions affect the dispersal tendency in C. clienta. Under laboratory conditions, individuals of C. clienta showed a higher tendency to disperse from previously grazed than from ungrazed pieces of limestone (their natural substratum), whereas conspecific density or presence of B. perversa had no effect. However, when snails had been kept on the pieces of limestone for 40 days prior to testing, dispersal tended to increase with increasing density of conspecifics. In the field, marked individuals of C. clienta were released at different densities on vertical rock walls. Density of conspecifics at the release points did not influence the distances travelled. Similarly, intraspecific density did not affect dispersal when the snails' food resource (lichens) had been experimentally reduced on the quarry walls. Neither was the dispersal tendency influenced by different crowding conditions experienced for 40 days prior to release. The discrepancy between the results of laboratory and field experiments suggest that additional factors acting on dispersal are of importance in natural populations of C. clienta.
Variation in number of ventral scales in snakes: effects on body size, growth rate and survival in the adder, Vipera berus
Authors: Lindell L. E. , Forsman A. , Merilä J.
Published: March 2009

The relationship between number of ventral scales, correlating with number of body vertebrae, and body size of adders, Vipera berus, was investigated using captive‐born young and wild‐caught adults (snout‐vent length > 400 mm) from six populations in eastern Sweden. Females had significantly more ventral scales, and were larger, than males in all populations. Among adult individuals, snout‐vent length was highly positively correlated with the number of ventral scales when differences due to sex and locality were controlled for. The same pattern was true for newborn individuals when differences due to litter and sex were controlled for. The influence of number of ventral scales on survival and growth rate as possible causes of this positive correlation was examined. Mean number of ventral scales was lower in new‐born snakes than in adults, indicating selection against individuals with a low scale count. Since this selection appears to take place in the early juvenile phase, it is inadequate to explain the relationship between adult body size and number of ventral scales. However, individuals with many ventral scales had significantly higher growth rates than individuals with few ventrals. This suggests that individuals with many ventral scales enjoy a higher growth rate and therefore are able to reach a larger size than their conspecifics of the same age with few ventral scales. This would explain the positive relationship between body size and ventral scale number observed in new‐born and adult snakes.
On measuring head length in fishes, amphibians and reptiles and on modified calliper rules
Authors: Goren Menachem , Werner Yehudah L.
Published: March 2009

The definition of head length in ichthyology and herpetology varies along four dimensions. Three may be taxon‐dependent: (1) the point selected as ‘the anterior end of the head’ (2) the location of ‘the posterior end of the head’ and (3) the degree of inclusion of soft structures at the posterior end of the head. But (4) is technical and has caused much confusion: whether to measure parallel to the long axis, or ‘point‐to‐point’, at an angle to the axis. In order to facilitate measurements which are standardized in this dimension, modified calliper rules are introduced.
The functional morphology of the alimentary canal of larval stages of the parasitic copepod Lepeophtheirus salmonis
Authors: Bron J. E. , Sommerville C. , Rae G. H.
Published: March 2009

The functional morphology of the alimentary canal of copepodite and chalimus stages of Lepeophtheirus salmonis (Krøyer, 1837) is described and compared with that found in other copepods studied to date.

The buccal cavity passes into a gut comprising three major regions: foregut (oesophagus), midgut and hindgut. The foregut and hindgut both posscss a cuticular lining whereas the midgut is lined with specialized epithelial cells. The midgut is divided into three recognizable zones, namely anterior midgut caecum, anterior midgut and posterior midgut. Three main types of epithelial cell are recognizable in the midgut: vesicular cells, microvillous cells and basal cells which correspond to the cell types normally described in other parasitic and free‐living copepod species.

Digestion is thought to occur in the midgut and be mediated by the epithelial cells that line it. Although several glands appear to discharge into the area of the buccal cavity, none was seen to interface to any other area of the gut. There was no evidence for the involvement of commensal gut bacteria in food digestion.
Sex differentiation and gonadal development in the diandric, protogynous wrasse, Thalassoma bifasciatum (Pisces, Labridae)
Authors: Shapiro D. Y. , Rasotto Maria B.
Published: March 2009

One hypothesis that would unify many of the apparently diverse patterns of gonadal differentiation in teleost fishes under a single conceptual scheme is that individuals develop in a female direction unless a masculinizing mechanism intervenes. We provided a descriptive test of this hypothesis in a diandric, protogynous wrasse in which males are produced through two, apparently different developmental sequences: ‘primary males’ develop testes as juveniles and remain male throughout life, while ‘secondary males’ develop ovaries as juveniles and later in adult life the functional ovary redifferentiates into a functional testis. The gonads of 128 individuals, from the smallest juveniles to full‐sized adults, were examined histologically. Gonads of the smallest juveniles were undifferentiated or contained young oocytes with no ovarian cavity and no testicular tissue. As individuals increased in size, the proportion of oocytic gonads increased. The distribution of gonad types for larger individuals suggested that a portion ofthese oocytic gonads developed into ovaries, while another portion lost its oocytic elements and became testes. These patterns supported the hypothesis that the gonads of all individuals, including primary males, passed through an initial female phase prior to differentiating into an ovary or testis. The structure of primary testes was not identical to the structure of secondary testes. The critical difference between the two types lay in the presence of a large central cavity in the latter that was not present in the former. Positional differences in the duct system were only found in the posterior region of the gonad and were the consequence of a lateral internal split in the secondary gonad resulting from confluence of the central cavity.
An ecomorphological review of the dodo(Raphus cucullatus)and solitaire(Pezophaps solitaria),flightless Columbiformes of the Mascarene Islands
Authors: Livezey Bradley C.
Published: March 2009

This paper describes a morphological study of the dodoRaphus cucullatusand solitairePezophaps solitariaextinct, flightless Columbiformes of the Mascarene Islands, Indian Ocean—based on mensural data from 387 skeletal elements, comparative data from four flighted species of Columbidae, ancillary mensural data from other Columbiformes, and the literature.

Raphus cucullatus and P. solitaria are characterized by great body size and substantially reduced pectoral limbs. Sexual size dimorphism is unusually great in bothR. cucullatusandP. solitaria,and sexual dimorphism ofP. solitariamay be the greatest of any carinate bird. Estimates of body mass (kg), based on femur lengths of flighted columbids and adjusted for flightlessness and seasonal deposition of fat, were: 21 and 17 for male and femaleR. cucullatus,and 28 and 17 for male and femaleP. solitaria,respectively. Pectoral reduction is greater in R. cucullatus than in P. solitaria, but both species are characterized by differential shortening of wing elements, changes in the sternum and scapulocoracoidal angle. R. cucullatus has disproportionately long femora, short tarsometatarsi and long digits, whereas P. solitaria has disproportionately long tibiotarsi, short tarsometatarsi and short digits; relative shaft widths of leg elements are substantially greater in bothR. cucullatusandP. solitariathan in flighted columbids.

As is typical of other birds, giantism ofR. cucullatusandP. solitariaprobably was associated with physiological changes, increased longevity, enhanced thermodynamic efficiency and improved capacity for fasting. Evidently bothR. cucullatusandP. solitariawere primarily frugivorous, and foraging‐related morphological peculiarities include an enlarged crop and the retention of ‘gizzard stones’. Both species had clutch sizes of one, and egg masses of the flightless species approximated that predicted for a flighted columbid of equal size. Extreme sexual dimorphism and territoriality ofP. solitariasuggest that the species may have been polygynous and perhaps lek‐breeding. The description of ‘gigantic immaturity’ inR. cucullatusby Strickland & Melville (1848) probably represents the first recognition of paedomorphosis in any species of bird. Pectoral underdevelopment and (in at leastR. cucullutus) comparatively ‘juvenile’ plumage in adults substantiate the role of paedomorphosis in the ontogeny of flightlessness inR. cucullatusandP. solitaria;both species also were characterized by peramorphic skulls, trunks and pelvic appendages. The common assumption of monophyly of the fligHtless species (it. Raphidae) lacks rigorous analytical support. In spite of the anthropogenous extinction of both species, bothR. cucullarusandP. solitariawere evolutionarily innovative in ontogeny, morphological characters and life‐history strategies.
Intraspecific variation in nemerteans (Nemertea): synonymization of genera Paroerstedia and Oerstediella with Oerstedia
Authors: Envall M. , Sundberg P.
Published: March 2009

Abstracts

Intraspecific variation in internal morphological charactcrs is substantial in many nemertean species, mainly due to the tendency for specimens to contract during fixation. It is shown that variation within the type species for the genus Oerstedia, O. dorsalis (Abildgaard, 1806), encompasses all the character states that have been used to erect the two related genera Oerstediella and Paroerstedia. These genera are synonymized with Oerstedia, and the validity of species previously assigned to these genera is discussed.
Comparison between aquatic and terrestrial locomotions of the leatherback sea turle (Dermochelys coriacea)
Authors: Renous Sabine , Bels V.
Published: March 2009

Kinematic characteristics of the fore‐ and hindlimb displacements during terrestrial and aquatic locomotions in juvenile marine turtles Dermochelys coriacea are compared. Modulations of the spatial displacements of the limbs and durations of the stance and swing phases are analysed in relationship with the constraints of the aquatic and terrestrial environments. The stance and swing phases used for describing the aquatic locomotion are re‐evaluated in the light of the spatial displacements of the forelimbs during complete beating cycles.
Conception rates following intrauterine insemination of European (Dama dama dama) fallow deer does with fresh or frozen‐thawed Mesopotamian (Dama dama mesopotamica) fallow deer spermatoza
Authors: Jabbour H. N. , McG. Argo C. , Brinklow B. R. , Loudon A. S. I. , Hooton J.
Published: March 2009

A total of 121 European fallow deer does, being either parous (n= 15) or nulliparous (n= 106), were treated with intravaginal progesterone impregnated controlled internal drug release (CIDR) devices for 14 days. The does were divided into three treatment groups and inseminated in utero by laparoscopy, at approximately 65 hours after CIDR device removal, with 25 × 106fresh Mesopotamian (n= 40), 25–35 × 106frozen‐thawed Mesopotamian (n= 41) or 30–32.5 × 106frozen‐thawed European (n= 40) fallow deer spermatozoa. The semen used had been collected, from two Mesopotamian and two European fallow deer bucks, by electroejaculation under general anaesthesia. Pregnancy was diagnosed by rectal ultrasonogrdphy on Day 50 after insemination.

There were no apparent differences in the quality of ejaculates between the two subspecies of fallow deer. The volume of semen and the total number of spermatozoa ranged between 0.6–1.2 ml and 2.11–4.95 × 109per ml of semen, respectively. Evaluation of frozen‐thawed spermatozoa revealed post‐thaw motility rates between 50–70%. The overall conception rate was 65.3%. A higher conception rate was observed following insemination with European than Mesopotamian frozen‐thawed spermatozoa (75% vs. 53.7%, respectively,P< 0.05). Insemination with fresh Mesopotamian spermatozoa increased the conception rate to a level not significantly different from that observed following insemination with European frozen‐thawed spermatozoa (67.5% vs. 75%, for fresh Mesopotamian and frozen‐thawed European semen, respectively).
The effect of pH on embryonic and larval development in smooth and palmate newts, Triturus vulgaris and T. helveticus
Authors: Griffiths R. A. , De Wijer P. , Brady L.
Published: March 2009

The distribution of smooth newts, Triturus vulgaris, and palmate newts, Triturus helveticus, in north‐west Europe is related to geology and water quality. This study compared the development of the eggs and larvae of the two species under sublethal acidic and neutral conditions. Newt embryos raised under low pH hatched at an earlier stage of development, at a smaller size, and before those raised under neutral conditions. T. vulgaris hatched at a smaller size than T. helveticus, but pH did not affect the species differentially. Larvae of both species grew to a larger size under neutral than under acid conditions. Larvae raised in heterospecific pairs grew at least as well as those raised in conspecific pairs. Feeding was depressed under acid conditions, and reduced growth may therefore be associated with changes in the behaviour of newt larvae and their prey.
The mechanical design of the tusk of the narwhal (Monodon nonoceros: Cetacea)
Authors: Brear K. , Currey J. D. , Kingsley M. C. S. , Ramsay M.
Published: March 2009

The mechanical properties of the tissues of the tusk of a narwhal Monodon monoceros, their histological arrangement, and the gross anatomy of the tusk were examined. The histology of the tusk shows various toughening mechanisms. The tusk tissues are of low stiffness, but are very tough, suiting the tusks for loading on impact, but not for longitudinal loading. These mechanical properties suggest the possible functions of the tusk, namely to be long in order to be sexually attractive, while being tough in order to withstand ‘testing’ blows from other males.
Fine structure of sacciform cells in the epidermis of the brown trout, Salmo trutta
Authors: López‐Dóriga M. V. , Martínez J. L.
Published: March 2009

The fine structure of a cell type in the epidermis of brown trout, Salmo trutta L., is described. Its cytological features are compared with those of other sacciform cells reported in several species of teleost fish. This cell type also has a highly electron‐dense cytoplasm with numerous Golgi systems and extensive rough endoplasmic reticulum. However, surrounding the large central vacuole there are no peripheral vesicles—‘bubbles’—which are characteristic features in non‐salmonid teleosts. Instead of these, in the vacuole there are cytoplasmic intrusions of circular cross‐sections forming a mesh in the cortical zone. Inside these intrusions there are granules which are interpreted as ribosomes trapped by fusion of the vacuole and reticulum membranes. The way in which the secretion is released into the lumen of the central vacuole is discussed. It is suggested that this proteinaceous material does not pass through the Golgi system, but flows directly from endoplasmic cisternae to the vacuole.
Contribution of internal bony trabeculae to the mechanical properties of the humerus of the pigeon (Columba livia)
Authors: Rogers R. R. , LaBarbera M.
Published: March 2009

Mechanical properties of the pigeon humerus are significantly influenced by internal bony trabeculae. Experimental testing of braced (intact trabeculae) and unbraced (trabeculae experimentally removed) humerus pairs extracted from the same individuals demonstrates that the flexural rigidity, strength and toughness (work of fracture) of the pigeon humerus are all augmented by an intact framework of trabeculae. Measured differences in mechanical properties in braced/unbraced comparisons generally exceed discrepancies attributable to random variation in construction and thus cannot be ascribed to inherent skeletal asymmetry. The structural contribution of bony trabeculae is apparently greater in subadult birds, possibly due to thickening of cortical bone and/or increasing mineralization of bone tissue with age.
Organochlorine residue concentrations and burdens in grey seal (Halichoerus grypus) blubber during the first year of life
Authors: Addison R. F. , Stobo W. T.
Published: March 2009

Between 1988 and 1991 grey seal (Halichoerus grypus) pups at various developmental stages were sampled at Sable Is., NS, and blubber samples were analysed for lipid content and organochlorine (OC) residue concentrations. Blubber lipid content increased significantly between birth and 12 d, and then stayed relatively constant. Blubber OC residue concentrations were fairly constant during the first 12–16 d of life. From weaning (approx. 16 d) until four months, the pups are learning to feed but are relying on blubber fat reserves; thus, during this period blubber weight declined to minimum levels, and OC residue concentrations in blubber lipid increased significantly. Blubber lipid OC concentrations then declined slightly as the pups gained weight, until at the end of one year they were about twice those immediately post‐weaning. Blubber lipid residue burdens calculated from these data showed that at weaning, about 98% of the seal's residues were accumulated from maternal milk. After weaning, there were no significant changes in the burdens of any residue until the end of the first year of the pup's life, and the organochlorine concentration changes reflected a fairly constant organochlorine burden around which lipid contents varied. These data suggest that the capacity of the seal to degrade the residue inherited from its mother is very limited. Furthermore, the absence of any significant accumulation of organochlorines during the second six months of the seal's life suggests that the juvenile seal must feed at a low trophic level which is not highly contaminated with organochlorines.
Population differentiation in scalation of the Iberian rock lizard (Lacerta monticola)
Authors: Brown R. P. , Pérez‐Mellando V.
Published: March 2009

The rock lizardLacerta monticolais a climatic relict confined to three mountain ranges and one coastal region of the Iberian peninsula. Scalation was studied in specimens from localities encompassing all major parts of its range. Population differentiation was analysed using analyses of variance, z‐transformations of within‐locality character‐correlations, canonical variate analyses, principal components analysis, and matrix association tests. Substantial differentiation was found between Pyrenees specimens and those from other localities, supporting a recent study which indicated that the Pyrenees populations could represent a different species. Considerable geographic variation is also found among populations from the remaining parts of its range, the pattern of which is not compatible with existing racial categories designated for this species.
Ovarian development in sexual and parthenogenetic geckos of the Heteronotia binoei complex
Authors: Whittier Joan M. , Dale Roberts J. , Stewart D. , Moritz C.
Published: March 2009

Ovarian development in sexual and parthenogenetic geckos of the Heteronotia binoei complex was analysed quantitatively by gross and histological examination. Females were classified into one of four stages of the reproductive cycle: non‐reproductive, preovulatory, postovulatory and postoviposition. Parthenogens had significantly more developing follicles present in the ovaries than sexual females in non‐reproductive, preovulatory and postovulatory stages of the reproductive cycle. The larger number of developing follicles in parthenogenetic Heteronotia was correlated with the significantly larger body size of the parthenogenetic females at the localities examined. Maximum follicular size and rates of follicular atresia were not significantly different between sexual and parthenogenetic females. These findings raise the possibility that the reproductive output of the parthenogenetic females may be higher than that of sympatric sexual females at these localities due to an increase in follicular recruitment. Based on this evidence, we predict that at these localities parthenogenetic females produce more clutches of two eggs than sexual females. If viability is equal, this would enhance the reproductive advantage of parthenogens over the two‐fold level already present. In all other respects, the morphology of the ovaries appeared very similar between parthenogenetic and sexual females and was typical of geckos.