bluuebunny/crossref_metadata_2025_split huggingface dataset:
Albumin evolution in West Indian frogs of the genus Eleutherodactylus (Leptodactylidae): Caribbean biogeography and a calibration of the albumin immunological clock
Authors: Hass Carla A. , Hedges S. Blair 
Published: March 2009

Antisera to serum albumins from five West Indian species of the frog genus Eleutheroductylus were prepared, and the reciprocal immunological distances (IDs) obtained were used to provide a time frame for the evolution of this group in the West Indies. One‐way IDS were obtained to 25 additional species within the genus, with emphasis on those from the West Indies. These immunological data support both a recent classification of Eleutheroductylus based on an analysis of slow‐evolving allozyme loci, and the monophyly of the 17 native Jamaican species as indicated by a more comprehensive electrophoretic study. This is in contrast to the results of morphological studies supporting multiple invasions of Jamaica by Eleutherodactylus. Within the subgenus Euhyas, IDS ranged from6–27 between Jamaican species, whereas between species on different islands the range was29–67. The subgenus Syrrhophus in southern North America was found to be the sister group to the subgenus Euhyus, a western Caribbean clade. Pelorius, a subgenus restricted to Hispaniola, was found to be the sister group of the subgenus Eleutheroductylus in the West Indies. The largest IDs obtained for West Indian species were those between the two major groups, the subgenera Eleutheroductylus and Euhyas.The albumin immunological clock for Eleutheroductylus was calibrated with three events in the geologic history of the Caribbean: the breakup of the proto‐Antilles (65‐75 million years before present [mybp]), the emergence of Jamaica (20‐30 mybp), and the uplift of the Blue Mountains in Jamaica (5‐10 mybp). Immunological distances corresponding to those events yield a calibration of 1 ID=0.60 million years (my), the same as that previously obtained for other groups of amphibians and thus supports the use of albumin immunological distance as a molecular chronometer in the genus Eleutherodactylus
Evolution and biogeography of West Indian Sphaerodactylus (Sauria: Gekkonidae): a molecular approach
Authors: Hass CarlaAnn 
Published: March 2009

This study investigated the phylogenetic relationships and biogeographic history of West Indian geckos belonging to the genus Sphaerodactylus through an analysis of protein variation. Two techniques were used: sequential starch gel electrophoresis of 15 slow‐evolving loci and microcomplement fixation of albumin. The relationships obtained were used to revise the classification of this genus. Two major groups (subsections) occur in the West Indies. The sputator subsection, centred in the Greater Antilles, is composed of three series: cinereus, sputator and argus. The fantasticus subsection, restricted to the Lesser Antilles, includes only the fantasticus series.Three antibodies (argus, asterulus and copei) were used to investigate albumin evolution and estimate times of divergence within Sphaerodactylus. Using the albumin clock calibration derived from other groups, the West Indian Sphaerodactylus had diverged from other sphaerodactylines by approximately 27 million years before present (mybp). Therefore, fragmentation of the Proto‐Antilles (60 mybp) apparently did not play a role in the group's evolution. The present distribution of West Indian Sphaerodactylus resulted from dispersal. Hispaniola probably was the centre of Sphaerodactylus diversity and the source of colonists for other islands. Certain features of Sphaerodactylus ecology and physiology make them likely candidates for dispersal. In contrast to the West Indian species of Anolis and Eleutherodactylus, few exampies of morphological convergence are found in Sphaerodactylus. Allopatric speciation, perhaps due to climatic changes in the Pliocene and Pleistocene, is suggested as the primary mechanism of species formation in West Indian Sphaerodactylus.
Life history and distribution of the small south‐western Atlantic octopus, Octopus tehuelchus
Authors: Iribarne O. O. 
Published: March 2009

Although this species has been reported from shallow waters down to 90 m depth, knowledge is almost entirely based on intertidal samples. In this study both intertidal and subtidal samples were taken during 1982–1987, in northern San Matias Gulf (41° S, 63° 30′ W). This is a large‐egged (eggs: 9–12 mm long ×–5 mm wide, stack of 4–6 mm long) and small‐sized (up to 150 g) octopus. Egg laying occurs between autumn and winter. Embryonic development takes about four months (water temperature:–19°C). Large hatchlings (DML: 5·64 mm, TL: 14·23 mm, TW: 0·139 g) emerge over spring and early summer, and development is direct. Maximum size is reached after 17–18 months; mating takes place in summer. Females reduce their feeding activity when they reach maturity, and cease eating while brooding. Mean life‐span is two years, but some individuals (mostly females) may live up to three years. Females approaching the beginning of the brooding period move to the subtidal zone, where males outnumber females until the end of summer and females (mostly brooders) then outnumber males. In the intertidal zone sex ratio was 1:1 from December to late March, but in April males outnumber females.These life‐history traits are compared with those of other large‐egged octopuses and are discussed in relation to environmental conditions prevailing in the San Matias Gulf.
The water relations of Lithobius forficatus and the role of the coxal organs (Myriapoda: Chilopoda)
Authors: Littlewood Henk 
Published: March 2009

The water relations of the common brown centipede, Lithobius forficatus (L.), are examined with regard to the possible involvement of the coxal organs in water uptake. Centipedes with blocked and open coxal pores are subjected to a variety of dehydration and rehydration regimes and weight change over time measured. Weight loss and regain is related to body surface area and is not influenced by the coxal organs.The conclusion of the paper is that the coxal organs of L. forficatus do not contribute significantly to the ability of these animals to recover water lost through cuticular transpiration.
The external morphology of the pseudoscorpion Roncus andreinii
Authors: Gardini G. , Benelli R. 
Published: March 2009

The external morphology of the four postembryonic instars of Roncus andreinii (di Caporiacco, 1925) is described and compared with one of the related R. lubricus L. Koch, 1873 (Gabbutt & Vachon, 1967), with particular emphasis on disposition of the chelal trichobothria in relation to growth.From the evaluation of characters it is concluded that a few morphometric and chaetotaxic characters (i.e. the length, ratio and shape of pedipalpal articles, the ratio of fingers/pedipalpal hand, the chaetotaxy of sternites II and III) represent good specific discriminants, while the relative position of trichobothria along the chelal axis is nearly the same in both species.The localization of the growing and non‐growing regions along the pedipalpal fingers may be of practical use in the search for new taxonomic characters.
Influence of flow rate and aldosterone administration on mandibular salivary composition in the koala:(Phascolarctos cinereus)
Authors: Beal A. M. 
Published: March 2009

The possibility of adaptations of mandibular salivary function to a diet of eucalypt leaves and for evaporative cooling was investigated in anaesthetized koalas. Salivary composition, at a range of flow rates up to maximum and during aldosterone administration, was measured in saliva evoked by intravenous infusion of carbamylcholine chloride. Maximum fluid secretion rates per gram tissue (230 ± 18·2 μl/min/g gland) were similar to mandibular glands of other species and about four times the rates/g gland reported for the parotid gland of koalas. Salivary concentrations of Na (6·1 ± 0·91 to 67·7 ± 3·51 mmol·l−1), Cl (7·2 ± 0·71 to 53·0 ± 2·82 mmol·l−1), HCO3(8·6 ± 0·81 to 19·4 ± 2·13 mmol·l−1) and the osmolality (26·7 ± 2·34 to 132·9 ± 5·47 mosmol.kg−1) were positively correlated with salivary flow rate. The concentrations of urea (1·87 ± 0·034 to 0·71 ± 0·099 mmol·l−1), K (13·0 ± 0·90 to 6·25 ± 0·482 mmol·l1‐), Mg (33·6 ± 2·53 to 10·1 ± 4·68 pmol·l−1), H+(246·2 ± 55·78 to 62·1 ± 8·01 &#x006e;̈mol·l−1) and PO4(3·46 ± 0·350 to 1·13 ± 0·044 mmol·l−1) were negatively related to flow rate. Total protein (411 ± 44·4 to 656 ± 146·4 mg·l−1) and total Ca (356 ± 45·2 to 467 ± 61·6 μmol·l−1) concentrations were not correlated with flow but were highly correlated with one another. With salivary amylase activity being absent and plasma amylase activity being very low indicating low production rates by other tissues, the koala is likely to have limited ability to digest starch. Intravenous infusion of aldosterone at 5 μg·h−1for 90 rnin followed by 50 μg·h−1for 105 min demonstrated that the gland responded rapidly to changes in endogenous mineralocorticoid levels. Mean salivary Na/K ratio before aldosterone administration was 6·9± 201, the ratio had fallen significantly (P< 0·05) after 75–90 min infusion and had fallen to 0·71 ± 0·172 by the last 30 min of infusion.It was concluded that the mandibular gland of the koala, with its relatively high secretory capacity and its sensitivity to stimulation, would have the major influence on the composition of mixed saliva during low‐flow reflex secretion. Additionally, because the gland is responsive to acute changes in mineralocorticoids and produces a markedly hypotonic saliva, the mandibular is better adapted than the parotid gland to be the primary source of saliva for evaporative cooling.
Phenotypic and genetic characteristics affecting lifetime reproductive success in female Cuvier's, dama and dorcas gazelles (Gazella cuvieri, G. dama and G. dorcas)
Authors: Alados C. L. , Escós J. 
Published: March 2009

Populations of Cuvier's, dama and dorcas gazelles were removed from the western Sahara to the Estacion Experimental de Zonas Aridas, Almeria, Spain, between 1970 and 1975. The life‐history records of all the females living between 1970 and 1988 were examined.Results show that fecundity is lower in young females than in middle‐aged females, and that juvenile mortality is higher in fawns of young females. The adult body length of Cuvier's and dorcas gazelles is affected by their early development but this does not apply to the dama gazelle. The adult body length and the birth weight are positively correlated with longevity in female Cuvier's and dama gazelles, but for the dorcas gazelle only birth weight is related to longevity. Juvenile survival and reproductive performance of the three gazelle species studied are not related to adult body length or birth weight.A high inbreeding coefficient reduces longevity in Cuvier's and dama gazelles but not in the dorcas gazelle. The effect of a high inbreeding coefficient is pronounced in the fecundity and juvenile survival of the female dama gazelle, less pronounced but evident in dorcas gazelle. The effects of inbreeding are minimal in Cuvier's gazelle and are evident only in the twinning rate. This result is surprising in view of the high inbreeding coefficient in Cuvier's gazelle relative to the other two species.As in many mammals, birth weights in the three species studied are closely related to the probability of survival during the first days of life. One of the causes of decreasing birth weight in male and female offspring of Cuvier's gazelles and in female offspring of dorcas gazelles is their inbreeding coefficient. The inbreeding coefficient of the mother also reduces the offspring's birth weight in both sexes of the dama gazelle, but there is no influence on offspring of Cuvier's or dorcas gazelles. On the other hand, only the birth weight of the male offspring of the dorcas gazelle is influenced by the birth weight of its mother. Mother's age and offspring birth weight are related for male offspring of Cuvier's and dama gazelles.
Chilopod coxal organs: morphological considerations with reference to function
Authors: Littlewood Henk 
Published: March 2009

A comparative account of the morphology of chilopod coxal organs is given with special reference to their possible function.Allometric relationships which exist between the size of the centipede and the number of coxal pores and organs are discussed in the context of size‐dependent physiological constraints which may affect the function of the coxal organs.
Variation in eggs and the period of rapid yolk deposition of the silver gull Larus novaehollandiae during a protracted laying season
Authors: Meathrel Catherine E. 
Published: March 2009

Silver gulls Larus novaehollandiae in south‐western Australia lay eggs over an eight‐month period with peaks in April, July and September. Clutch‐sizes, egg‐sizes and laying‐intervals did not differ between these three peaks, hut second eggs were smaller than first‐laid eggs on each occasion.Rapid yolk deposition took 7–14 days. Daily increments of yolk growth were neither constant nor maternally influenced. The yolks of first‐laid eggs were laid down faster than the yolks of subsequent eggs. Egg size, weight and composition, as well as the period of rapid yolk deposition, may be proximately linked to the age, breeding experience, and body condition of laying females.
Refuge strategies and habitat segregation in two sympatric rodents Otomys unisulcatus and Parotomys brantsii
Authors: Plessis Amanda Du , Kerley G. I. H. 
Published: March 2009

The possibility of different refuge strategies resulting in habitat segregation in two sympatric rodents, the bush Karoo rat, O. unisulcatus and the whistling rat, P. brantsii was investigated. The rodents' habitats were characterized by using the multivariate analysis procedures: ordination diagrams and hierarchical classification. The most important environmental variables were identified. Otomys unisulcatus was restricted to areas with high percentage plant cover (60.6%) and dense foliage compared to P. brantsii habitat (plant cover=34.8%). The high percentage plant cover is necessary for nest construction. Parotomys brantsii habitat was characterized by deep Soil (76.9+15cm) with larger soil particles (0.31+0.2mm) compared to 47.5+30.3 cm soil depth and 0.15+0.1 mm soil particles in O. unisulcatus habitat. A suitable substratum therefore determines distribution of P. brantsii.The different refuge strategies result in habitat segregation and may be an important means of partitioning resources between these two sympatric rodents which have comparable body sizes, adtivitym dietary and thermoregulatory patterns.
The spatial organization of otters (Lutra lutra) in Shetland
Authors: Kruuk H. , Moorhouse A. 
Published: March 2009

The dispersion of otters Lutra lutra was studied along the coasts of an area of Shetland. The population was relatively stable, with about one adult otter per kilometre of coast. They fished diurnally in a strip of water usually within 100 m of the shore. Females lived in exclusive group ranges, occupied by up to four females, with well‐defined boundaries which were respected by successive occupants. For two groups, where relatively complete information was available, range size was 4.7 and 6.4 km, occupied by two and four females, respectively; a third range was about 14 km, with possibly 4–5 females. Within the group ranges individual females moved on their own or with their cubs. Each had a core area, where they were observed > 50% of the time; these core areas were separate from each other, although each individual used the entire group range. Several or all females in each range bred in any one summer. Male ranges were larger than those of females, and overlapped with two or more female group ranges; there were several resident males along each section of coast, but the information on males was incomplete. The habitats of the sexes were different; males spent more time on exposed coasts than did females. There were frequent visits to all coasts from non‐resident otters of both sexes.Behavioural interactions related to territoriality are described; otters showed little overt aggression, except between adult males, but there was some individual avoidance. It is argued that the survival value of this spatial organization can be understood in terms of resource dispersion, but several types of resources have to be considered (including prey and fresh water), and detailed predictions of spatial organization from resource dispersion are unwarranted.
The significance of four xeric parameters in the ecology of terrestrial Tardigrada
Authors: Wright Jonathan C. 
Published: March 2009

Tardigrades were sampled from diverse biotypes and classified according to four xeric variables to assess susceptibility to desiccation: exposure to insolation, elevation, and standardized desiccation rate and hydration capacity of the habitat plant. Fifteen tardigrade species were recorded including Hypsibius cataphractus Maucci, a new addition to the British fauna.Xeric associations with seven tardigrade species were analysed by multiple regression, using incidence and population density as independent abundance estimates. Species show considerable variation in ecotype. The hygrophilic Macrobiotus hufelandi and Hypsibius dujar dini are excluded from rapidly desiccating habitats. Xerophiles, Milnesium tardigradum and H. oberhaeuseri, do not favour high insolation or high desiccation rate but apparently shun poorly drained sites and/ or prolonged hydration. Significant interspecific associations are identified between Milnesium tardigradum and two Hypsibius species which it may exploit for food. Negative associations between three other species—M. hufelandi, M. richtersi and H. prosostomus—suggest competitive exclusion.The interstitial meiofauna of a dehydrating moss cushion migrates vertically to the proximal C‐zone, although this behaviour is not observed in Echiniscus testudo; implications of this for the species' ecotype are discussed.
Larvae of Maculinea rebeli, a large‐blue butterfly and their Myrmica host ants: patterns of caterpillar growth and survival
Authors: Elmes G. W. , Wardlaw J. C. , Thomas J. A. 
Published: March 2009

Maculinea rebeli caterpillars spend their final instar as specific parasites of colonies of the ant Myrmica schencki. This paper describes 14 experiments in which 604 caterpillars were reared with six species of Myrmica. About 40% of caterpillars died during an initial period of integration: survival was significantly greater among the larger caterpillars, in M. schencki nests, and in nests that had ant‐brood present. The growth of the survivors was extremely variable. After three weeks they had gained 2–18 times their initial body weight and appeared to belong to two distinct types: fast and slow developers. Only 11% of caterpillars died during the next 37 days of growth, before a fall in temperature to below c. 14 d̀C caused them to overwinter. By then, the caterpillars weighed from 5–90 mg (mean 22 mg).Caterpillars of all weights lost 33% of their mass during winter, and 8% died, before rising temperatures caused growth to resume in spring. Ofthe 363 that survived winter, 44% died during a period of spring growth and 12% pupated after about seven weeks. The latter came mainly from the largest caterpillars before winter and pupal size (mean weight 81 mg) was also related to prewinter caterpillar size. The remaining 44% of post‐winter caterpillars continued to grow slowly and then entered another quiescent phase and were still alive after one year in the nest. A small number of these pupated in the second year, an average of 404 days after adoption.It is calculated that an average‐sized Myrmica schencki colony of 350 workers can produce 4–5 adult butterflies; this laboratory result agrees well with field observations. The results are discussed in the light of a previous behavioural study.
Movements, diving and foraging behaviour of grey seals (Halichoerus grypus)
Authors: Thompson D. , Hammond P. S. , Nicholas K. S. , Fedak M. A. 
Published: March 2009

This study presents the first direct observations of the movements and behaviour of free‐ranging grey seals at sea. Radio and ultrasonic transmitters were attached to three sub‐adult male grey seals which were then tracked from a suitable vessel. Behaviour at sea fell into one of three categories: travelling between haul‐outs, short duration trips, and resting adjacent to haul‐out sites. Travelling was characterized by direct, relatively fast horizontal movement and by V‐shaped dive profiles. During short duration trips the seals swam slower and invariably exhibited square‐wave dive profiles, spending approximately 60% of total dive duration at the maximum depth. Resting involved shallow dives close to haul‐out sites and an absence of directed lateral movement.The excellent navigational abilities of grey seals are illustrated by the rapid, direct swimming between distant haul‐out sites. It is proposed that short duration trips are specifically for foraging because of their association with other piscivores, and because swimming was slow and mostly on or near the sea bed (grey seals are known to feed almost exclusively on demersal and benthic fish). These trips accounted for only 14% of the nine days that seal 1 was tracked. It is also proposed that the habit of diving to the sea bed whilst travelling between distant haul‐out sites is to allow opportunistic foraging with only a small increase in total swimming distance.
Spatial organization and monogamy in the mara Dolichotis patagonum
Authors: Taber A. B. , Macdonald D. W. 
Published: March 2009

Maras, Dolichotis patagonum, were observed and radio‐tracked in Argentina. They travelled as monogamous pairs that bred either alone at solitary burrows or communally at settlements where up to 29 pairs shared warrens.Members of a mara settlement grazed within 2.5 km of the communal warrens, using intensively about 1 ha per day, within drifting daily ranges of 11 ha, seasonal ranges of 98 ha and annual ranges of 193 ha.Their home ranges drifted continuously. Consequently, the long‐term movements of neighbouring pairs overlapped substantially, but at any given moment they were territorially spaced.Monogamous, drifting territoriality is explained by the patchy dispersion of food, the need to minimize interference competition, and a cycle of grazing and fallowing in the use of food plants.Two hypotheses explaining the adaptive significance of settlements are evaluated: one relates to resource availability (through the indirect effect of ground water and sheep dung on vegetation); and the other relates to predation (through the protective influence of human dwellings). The size of sheep flocks grazing at outstations during January provide a measure of the resource richness of patches where maras graze, and the richness of these patches in the dry season appear to limit the number of maras breeding at each settlement during the following wet season.Maras face extremes of resource dispersion between the wet and dry seasons: in the former, sparsely dispersed grazing and interference competition favour spacing out and territoriality; in the latter, clumping of resources facilitates pairs congregating in herds around outstations and dry lagoons. Superimposed upon the ecological factors favouring spacing out during the wet season are the sociological factors that cause the maras to den communally. The resulting compromise is a social system unique among mammals.