bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neurosecretion and water balance in the male desert locust (Schistocerca gregaria)
Authors: Highnam K. C. , Hill L. , Gingell D. J. 
Published: August 2009

Cautery of the cerebral neurosecretory cells in the immature male desert locust results in a retention of water and a consequent dilution of the haemolymph. If such cauterized locusts are given an excess water load this is lost far more slowly than in control animals; further, water is lost at a much slower rate in water loaded decapitated males than in decapitated males given a water load containing neurosecretory material (extract of corpora cardiaca).The histology of the neurosecretory system of the adult male desert locust is in all respects similar to that of the female. In the mature male most of the cerebral neurosecretory cells are histologically “full”, and injection of distilled water into such locusts results in a significant decrease in the number of “full” cells, indicating a release of neurosecretory material. Injection of 10% sodium chloride does not result in any such change.Allatectomy of males results in an accumulation of neurosecretory material in both the cerebral neurosecretory cells and corpora cardiaca. Injection of distilled water into these locusts results in a significant decrease in the number of “full” cells and injection of 10% sodium chloride does not result in any change.These results are consistent with the idea that the cerebral neurosecretory system produces a diuretic factor. However, as yet, no observations have been made of the effects of neurosecretion on the Malpighian tubules and so the possibility that the neurosecretory system is not directly related to the general mechanism of water balance remains open.
The pelvic girdle and fin in certain Indian hill stream fishes
Authors: Saxena Subhash Chandra , Chandy Mary 
Published: August 2009

This paper deals with the functional morphology of the pelvic girdle and fins in various genera of hill stream cyprinid and sisorid fishes. The pelvic plate of Pseudecheneis shows the greatest modification; it is unusually large and reaches the coracoids of the pectoral arch in front.The elaborate working of the pelvic muscles and their function in bringing about effective adhesion by the pelvic fins is described in detail. The formation of a new muscle, M. pars retractor ischii of the M. mesioventralis, is reported in Garra and Psilorhynchus (Cyprinidae) and in Glyptothorax and Pseudecheneis (Sisoridae). In Pseudecheneis, the complete separation of this muscle from the M. mesioventral, and modification of the M. protractor ischii, are discussed in relation to the crawling habit of the genus. The appearance of the M. arrector pel vicalis ventralis in Glyptothorax and Pseudecheneis among sisorids has been associated with the adhesive function of the outer ray.
Adhesive apparatus in certain Indian hill stream fishes
Authors: Saxena Subhash Chandra , Chandy Mary 
Published: August 2009

The results of a detailed study on the adhesive apparatus of Indian hill stream cyprinid and sisorid fishes are presented. The structure of the mental suctorial disc in the genus Garra is described. Histological study of the mental region of Crossocheilus and Psilorhynchus has also been made and compared with the mental disc of Garra. The muscles of the disc which control its movements in bringing a partial vacuum during adhesion have been investigated. The complexity of the geniohyoideus muscles in Garra is interesting. Variations in the degree of development and histological modifications of the mental disc are exhibited by the fishes of the genus Garra.A thoracic adhesive apparatus in the form of longitudinal or transverse ridges and grooves is present in the sisorids, Laguvia, Glyptothorax and Pseudecheneis except Gagata. A close study has revealed that the adhesive apparatus of the catfishes works mainly on the principle of friction. The variations in shape, size and location of the adhesive apparatus in various species are correlated to their respective habitats.Structural variation in the adhesive apparatus of Pseudecheneis is maximum in comparison to that in Laguvia and Glyptothorax. It is discovered that the modifications are associated with the presence of multi‐spinous layers, formation of caps by the basal or holdfast cells and with the transformation of loose areolar tissue into thick collagenous dermis. The presence of a pad of adipose tissue in the region of the adhesive apparatus has been reported and its physiological significance as a source of stored food suggested.The anterior part of the protractor ischii muscle is modified to control the action of the adhesive apparatus. In Pseudecheneis, besides the m. protractor ischii, the ventral part of m. mesioventral is also associated with the adhesive apparatus.
The morphology of the head, thorax, proboscis apparatus and pygidium of the maldanid polychaetes Clymenella torquata and Euclymene oerstedi
Authors: Pilgrim Muriel 
Published: August 2009

A detailed description is given of the anatomy of the head, thorax, proboscis apparatus and pygidium of the maldanid polychaetes Clymenella torquata (Leidy) and Euclymene oerstedi (Claparède) (=Caesicirrus neglectus Arwidsson, 1911). The head consists of prostomium, peristomial region and one achaetous segment which is undoubtedly a metamere. Whether the peristomium should be counted as another rests on the definition of a metamere, about which opinions differ. Evidence is presented which suggests that each of the two paired groups of proboscideal retractors is derived from a head septum.Probably because of the relatively large size of the proboscis, not only the head, but also the first four chaetigers (= thorax) act as a pump to effect the eversion of the proboscis by coelomic fluid pressure. The thoracic septa are highly specialized in relation to this function. In both gross and detailed anatomy, and in mode of functioning of the region, the maldanids show many resemblances to some arenicolids.The pygidium consists of a ring‐shaped thickening (the callus ring), the anal funnel and the anal cone.Based on this investigation of anatomy, a system of description is suggested which aims to avoid ambiguity and to eliminate from future maldanid literature the type of confusion which exists in it at present.
Variation in the distribution of pigment within the shell structure of birds' eggs
Authors: Harrison C. J. O. 
Published: August 2009

Very little comparative study has been made of the distribution of pigments within the structure of the egg‐shell. The present paper is a general account of the distribution of the pigments within the thickness of the egg‐shells of the different avian genera, and was undertaken in order to assess the value of this character for taxonomic purposes. Egg‐shells tend to cleave along a radial plane and the radial surfaces of shell fragments were examined under a microscope and the distribution of colours noted.Only two pigments are known to be present in most eggs, a blue biliverdin and a protoporphyrin responsible for reds, browns, blacks and yellows. The distribution of colours as it appears in fragments of egg‐shells of the different avian families is described, those of the Passeriformes being discussed as a single group. In general, the shells appear white or blue, with other pigment present either as a thin superficial layer, or in small patches scattered at intervals through the thickness of the shell. In 11 genera, various pigments were found to be present through a significant portion of the outer shell structure; from one‐third to one‐half the total thickness. There did not appear to be any common factor underlying this occurrence.The only major variation in distribution was found in patterned eggs, some of which had all the pigment producing the pattern limited to the surface layer of the shell, while in others this was present at varying depths within the thickness of the shell. The former type was found in eight families only, and in three of these, Falconidae, Opisthocomidae and Jacanidae, was limited to one family in an order containing numerous families.Fugitive pigments occur in some shells. An unstable porphyrin gives a pink flush only seen in very fresh eggs. In a few species the fresh eggs are green but subsequently become blue. The green colour appears to be due to a combination of blue biliverdin and a yellow pigment, possibly bilirubin.In view of the general similarity of pigment distribution in most egg‐shells this character would appear to have limited use in taxonomy, but the difference in distribution of pattern pigments might be of some significance.
The soil fauna as a food source for moles
Authors: Raw F. 
Published: August 2009

Moles feed mainly on insects and earthworms and may eat 18 to 36 k (40 to 80 lb) per annum, collected in an area of about 1/25 hectare (1/10 acre). This largely restricts them to deciduous woodland and old grassland on “mull” soils since field populations of soilinsects cannot provide them with enough food but earthworm populations can. Slugs and millipedes may be relatively unpalatable.Caches of earthworms stored by moles consist almost entirely of Lumbricus terrestris immobilized by removal or multilation of the anterior 3–5 segments. It is still uncertainhow and when the caches are made. Earthworm cocoons are prominent in the diet of moles in pastures but how they are located is not yet known.
Patterns of gill ventilation in some decapod Crustacea
Authors: Arudpragasam K. D. , Naylor E. 
Published: August 2009

The frequency of reversal of the respiratory current is recorded for Cancer pagurus, Macropipus puber, Corystes cassivelaunus and Homarus gammarus by cannulating the gill chamber and recording pressure changes therein. The predominant respiratory current flows backwards in Corystes and forwards in the other three, but all show rhythmic reversals of that current which appear to form an integral part of the mechanism of gill ventilation. Reversals appear to have significant gill cleaning functions only in Homarus andperhaps also Corystes.Measurements of gill ventilation volumes support these findings. Macropipus puber takes in almost all respiratory water at the bases of the chelae, anterior to the gills, and it shows a high reversal frequency apparently to irrigate the posterodorsal aspect of the gills. Cancer pagurus takes in a considerable volume of respiratory water at the bases of the last pair of peraeopods in addition to that entering at the bases of the chelae. This species shows fewer reversals, since the posterior gills are irrigated during normal forward flow, but artificial closure of the posterior openings results in an increased reversal rate.Comparisons are made of the gill ventilation patterns of all these species, together with Carcinus maenas described previously, and their functional inter‐relationships are discussed.
A study of the egg shells of the Falconiformes
Authors: Tyler C. 
Published: August 2009

A study of a selection of egg shells of the Falconiformes has been made similar to the earlier ones on ratites, the Anatidae and the Sphenisciformes. Chemical analyses, and histological and plastic embedding techniques were used.The main part of the shell in all species studied consists of large crystals running through the shell. There was no layer of fine vertical crystals above this and no cover, and even the cuticle was not very pronounced. Histological studies showed no major differences, except that some shells had vacuoles in the outer layers. All such shells also gave an unetched outer layer when plastic embedded radial sections were studied and thin sections showed spaces between and within crystals. These spaces in the outer layers of the shell were of taxonomic interest for they were not present in the Cathartidae, the Falconidae and Sagittarius serpentarius.Pore channels appeared to be much sparser than in other orders so far studied and all pores were single. Pigment was present on the surface of some shells, but it was also found in different layers of the shell right down to the cone layer and, in one case, had leaked through on to the membrane.There were significant relationships between total and soluble shell nitrogen which divided the Falconidae from most of the Accipitridae but left Pernis and Pandion in an intermediate position.
Observations on the venous system of three species of Polypterus (Pisces)
Authors: Magid A. M. Abdel 
Published: August 2009

The venous system of Polypterus exhibits general asymmetry. The features that characterize the venous system of this peculiarly African fish are the possession of many blood sinuses, the segmental drainage of blood, the continuation of the posterior cardinal veins as separated vessels and the occurrence of several anastomozes between the latter.In the absence of any recent comprehensive work on the blood system of this fish, it was thought that investigation of the circulatory system of Polypterus would be valuable. In this paper attention is drawn to Budgettapos;s (1902) original work on a larva of Polypterus senegalus. Contrary to Budgettapos;s findings it is concluded that what he called the “interrenal” vein is in fact the right posterior cardinal vein. It is also found that paired posterior cardinal veins exist in all adults.
Sisor rabdophorus—A study in adaptation and natural relationship III. The vertebral column, median fins their musculature
Authors: Mahajan C. L. 
Published: August 2009

A detailed description of the vertebral column, median fin skeleton and musculature is given. Comparisons based on the study of these structures in Gagata and Loricaria have been made. It has been clearly demonstrated that these structures in Sisor bear an unmistakable imprint of the bottom‐living habit of the fish and as such show a remarkable series of convergent modifications with the most highly specialized catfish family, Loricariidae, while Gagata shows an intermediate stage between the typical siluroid condition and the extreme type of modifications found in Sisor and Loricaria.That Sisor diverged early from the main stem of sisorid evolution is further supported by this study.
Studies on the ecology of field mice and voles (Apodemus sylvaticus, Clethrionomys glareolus and Microtus agrestis) in Houghall Wood, Durham
Authors: Ashby K. R. 
Published: August 2009

In a 12‐year study on Clethrionomys glareolus, Apodemus sylvaticus, and in less detail, on Microtus agrestis in an area of mixed woodland just south of Durham it has been found that a variety of mark‐and‐recapture line trapping has provided reliable indices of abundance, making it possible to follow the changes occurring in the populations of the three species. Parameters investigated included distribution, density, sexual condition, sex ratio, mortality, recruitment, growth and variation in pressure on food supplies.The abundance of Clethrionomys has varied cyclically, the periodicity being slightly under four years as previously recorded in the microtine rodents of tundra and grassland habitats. There has been evidence of abnormalities of the generations living during a crash similar to those reported in Microtus agrestis during this phase of a population cycle. Apodemus in contrast has had only a well‐defined annual fluctuation in abundance, the rapid decline observed in its population density each spring perhaps being caused by an intensification of territorial behaviour at the beginning of each breeding season. lntraspecific competition also appears to account for male Apodemus, which grow more quickly and to a larger size than females, being more abundant than the latter in most years. After exceptionally favourable seasons, females are as numerous as males, apparently as a result of a temporary reduction of such competition. Microtus, for which the area of study provided a marginal habitat, showed less regular fluctuations in abundance than have been found to occur in this species on moorlands.It is confirmed that Clethrionomys and Apodemus are important in woodland ecosystems as agents transporting, burying and eating tree‐seed, and damaging or killing the seedlings. Their influence on regeneration of forest is complex and calls for detailed study.The pressure exerted by these two species on token supplies of seed which were offered, was greatest in winter and least in late summer. Appetite and stockpiling activity were increased relative to rodent abundance, under crowded conditions. The significance of food shortage and of social stimulation respectively as possible causes of these increases are discussed.
Teeth as indicators of age with special reference to Red deer (Cervus elaphus) of known age from Rhum
Authors: Lowe V. P. W. 
Published: August 2009

An experiment in land management and Red deer population control was begun by the Nature Conservancy on the Isle of Rhum, a National Nature Reserve off the west coast of Scotland, in 1957. To assess the results fully it has become necessary to determine the most suitable ageing method which can be applied to the material, which has accumulated since from the annual deer culls and natural deaths.Using mandibles only from individuals, whose age was certainly known by marking at birth, and which, in most cases were shot by mistake during subsequent annual culling operations, four different techniques were critically tested. These comprised correlating various combinations of jaw and tooth measurements with age, examining the nature and quantity of secondary dentine deposited within the crown of the first incisor, interpreting the number of layers in the pad of cementum beneath the crown of the first molar, and assessing the stages reached in tooth replacement, eruption and wear. Of these various methods, ageing by tooth replacement, eruption and wear proved the most reliable.
Studies on the neursecretory system of the female mole cricket Gryllotalpa africana (Orthoptera: Gryllotalpidae)
Authors: Dogra G. S. 
Published: August 2009

The neurosecretory system of the mole cricket Gryllotalpa africana Beauvois, using PF and PAVB techniques, has been described in detail. Two types of cells, A‐ and B‐cells, have been observed. While the A‐cells are present in the pars intercerebralis medialis the B‐cells are distributed in the pars intercerebralis medialis and lateralis. On the basis of differences in size and appearance A‐cells have been subdivided into two, A1‐ and A2‐subtypes. Six stages for the accumulation of NSM in the A1‐cells have described. The variations in the shape of A1‐cells and reduction in their sizes have been correlated with the physiological state of the cells.The formation of the median neurosecretory pathways by the convergence of the proximal portion of the axons of A1‐cells, their crossing over and their emergence from the ventral side of the protocerebrum as the NCC I have been demonstrated convincingly. The NCC 11, reported for the first time in the mole cricket, joins the NCC I shortly behind the protocerebrum. Each common NCC joins the corpus cardiacum of its side apically and its nerve fibres penetrate the gland in a fan‐like fashion. The state and appearance of the NSM aggregates under transport, from the centre of elaboration to its storage centre, are described. The NSM is stored in the entire corpus cardiacum larger amounts being concentrated along the aorta wall and in the posterior half of the gland. The possibility of elaboration of NSM in the cells of the corpora cardiaca has been considered. A commissure, ventral to the aorta and posterior to the hypocerebral ganglion, joins the corpora cardiaca, through which passage of NSM occurs.In mature females, in contrast to the immature ones, the number of A‐cells containing the SM is greater, the amount of NSM in the cells is larger and the number of their activity cycles is greater. From these features, and from the presence of larger amounts of NSM in the corpora cardiaca it is inferred that the neurosecretory system of mature female is more active than those of the immature females.
“Necking” behaviour in the giraffe
Authors: Coe Malcolm J. 
Published: August 2009

Previous references to “necking” behaviour, and the main features of the study area are briefly outlined.“Necking” behaviour in giraffe takes place only in all male herds. When the animals are in a head to head posture the intensity is either high or low, but when animals take up a head to tail posture the actions are always of high intensity and appear to have greater sexual significance.The significance of “necking” is discussed, and it is suggested that these ritualized actions form an important sexuo‐social bonding mechanism whereby a hierarchy is created amongst the males, and movement between strictly bachelor and mixed herds helps to maintain contact between the sexes in this polygamous mammal.
The diet of the dog‐whelk, Nucella lapillus (Gastropoda Prosobranchia)
Authors: Largen M. J. 
Published: August 2009

The information at present available suggests that, when adult, Nucella lapillus may prey upon a considerable number of different species, but that the diet of recently hatched dog‐whelks is rather more restricted. The food preferences of young Nucella have been investigated and it has been concluded that, while the diet of young and adult animals may differ to some extent, it is probably equally varied at all ages, and that cannibalism may be a frequent occurrence amongst all age groups.It has been determined that the size of the prey influences the selective predation of Mytilus by Nucella. Dog‐whelks show a marked preference for mussels in the 1 to 3 cm size range which may possibly be identified chemotactically.
The distribution and variation of Daphnia lumholtzi (Crustacea: Cladocera) in relation to fish predation in Lake Albert, East Africa
Authors: Green J. 
Published: August 2009

In Lake Albert Daphnia lumholtzi is found in two forms. One has a pointed anterior prolongation, or helmet, on the head. The other has a shorter rounded head, and was originally described as a separate species, D. monacha. The latter form dominates the zooplankton in the middle of the lake where planktivorous fish are rare or absent. The helmeted form becomes commoner near the margins of the lake and reaches its greatest abundance in Ndaiga Lagoon, where planktivorousfish are common. The possession of a helmet is associated with a reduction in the size of the carapace compared to the round headed form. The carapace with its contained eggs is the most conspicuous part of a cladoceran, so that the helmeted forms are at an advantage in the presence of planktivorous fish which locate their prey by sight. The mid‐lake monacha forms are larger than specimens of the same form in Ndaiga Lagoon, where it is shown that Alestes baremose feeds selectively on the larger specimens of the monacha form.The helmeted form produces more, but smaller eggs than the monacha form. The total brood volume (= mean egg volume x mean number eggs per female) is greatest in the midlake monacha forms. The selective advantages of variations in egg size and the possession of a helmet are discussed. It is concluded that the data from Lake Albert support the hypothesis of Brooks (1965) concerning the adaptive significance of helmet development in Daphnia.