bluuebunny/crossref_metadata_2025_split huggingface dataset:
The histochemistry and infrastructure of the coelomocytes of species of Lumbricillus, and observations on certain other enchyfraeid genera (Oligochaeta: Annelida)
Authors: Richards K. Sylvia 
Published: August 2009

The main coelomocyte type–the granular mucocyte–of Lumbricillus mirabilis, L. reynold‐soni and L. rivalis has inclusions consisting of a mucopolysaccharide‐protein complex with very low lipid levels. Both neutral and carboxylated acid mucopolysaccharides occur, the latter predominating in the granules of L. rivalis in which protein levels are lower than in the other two species.The Golgi‐derived granules of the mucocytes of L. mirabilis and L. reynoldsoni are electron dense when mature and are separated from each other by cytoplasm housing, generally, a single endoplasmic reticulum profile. The mucocytes arise from the peritoneum. In L. rivalis the inclusions are of finely fibrillar material typical of acid mucopolysaccharides. Studies on species of other genera show the species of littoral origin to possess mucocytes with an ultrastructure similar to that of the littoral L. mirabilis and L. reynoldsoni; those of non‐littoral origin are similar to the non‐littoral L. rivalis. The differences therefore appear to be eco‐physiological rather than taxonomic.Amoebocytic coelomocytes occur and two types are described for L. mirabilis and L. reynoldsoni. Type I is finely pseudopodous and contains numerous small, electron dense inclusions. The origin of Type I from the peritoneum is demonstrated. Type II is characterized by fewer pseudopodia and large, electron dense inclusions similar to chloragosomes. Pinocytotic vesicles occur at the cell periphery. No intermediates between Type I and II were observed, and Type II was not seen in L. rivalis. Both types occur in Enchytraeus albidus, but only Type I in Fridericia bulbosa and no amoebocytes were observed in Mesen‐chytraeus sp.
Interspecific competition in the shrews Sorex araneus and Sorex minutus (Soricidae, Insectivora): a population study of the Irish pygmy shrew
Authors: Ellenbroek Frans J. M. 
Published: August 2009

Sorex araneus and S. minutus, which are likely to show a temporary vertical habitat segregation, are largely sympatric, except in Ireland, where S. minutus occurs alone. Two mechanisms for this segregation may be suggested: a direct interspecific interaction or an evolutionary fixed relationship.Population densities and surface activity were measured, both in areas where the two species occur together (The Netherlands) and in areas in Ireland, in (order to investigate the possibility of a habitat shift and its influence on population density. No such effect was found in the present study.
The evolution of the premaxillary protrusion system in some teleostean fish groups
Authors: Gosline William A. 
Published: August 2009

Changes in the acanthopteran (acanthopterygian) system of premaxillary protrusion are traced from its incipient representation in the iniomous (myctophiform) genus Aulopus to its fully evolved form in the percoids. Two complementary components of the system are differentiated. One is the protrusion of the premaxillary, brought about primarily by the anteroventral movement of a ligament attached to the rostral cartilage. The second, which distinguishes the acanthopteran system from other types of jaw protrusion, is the emplacement of a bony maxillary wedge between the skull and the protruded premaxillary.The acanthopteran type of protrusion appears to have evolved in large‐mouthed fishes, with the lateral expansion of the gape that occurs in such forms a fundamental element of this system's mechanics. The modifications that occur in small‐mouthed fishes with little or no lateral expansion of the gape are discussed.Premaxillary protrusion was investigated in available fish groups sometimes placed between the iniomous fishes and the percoids in classifications. Of these groups, the beloniform and cyprinodont fishes have developed protrusion systems of non‐acanthopteran types.
The biology and functional morphology of Periploma (Offadesma) angasai (Bivalvia: Anomaiodesmata: Periplomatidae
Authors: Morton Brian 
Published: August 2009

The extremely rare Periploma (Offadesma) angasai Crosse & Fisher 1864 is a member of the widely distributed Periplomatidae (Anomalodesmata) occurring on surf‐protected beaches in New Zealand and Australia. The species is low intertidal‐sublittoral in distribution, living 7–8 cm below the sand surface on its left valve with separate siphons projecting to the sand‐water interface above. The shell is sharply inequivalve (the right deeply, the left shallowly convex) and inequilateral, the posterior rostrate and truncate and covered by thick periostracum densely studded with sand grains. These are attached to the periostracum by a sticky secretion produced from radial mantle glands in the middle mantle fold. Similar glands have been reported for members of the Lyonsiidae and Verticordiidae. Offadesma angasai is adapted for a life in which large amounts of fine sediment may enter the mantle cavity. Thus the ciliary rejection currents are powerful, the labial palps are extremely long and the sediments are bound up in mucus produced by an extensive gland, particularly in the right mantle lobe, in the posterior region of the mantle cavity. A gland with a similar structure but different staining reactions also lines the visceral mass and the mantle of the supra‐branchial chamber and probably consolidates particles penetrating the ctenidial filter. Such glands are similar in structure and function to the primitive molluscan hypo‐branchial gland.In many respects, especially with regard to the secondary ligament of fused periostracum, a ctenidial structure with type E ciliation, the presence of a 4th pallial aperture, extensive mantle fusions and simultaneous hermaphroditism, Offadesma is clearly similar to the majority of the Anomalodesmata. As in many other anomalodesmatans also, large, yolky, encapsulated eggs are produced; these are thought to be an adaptation facilitating survival by a sparsely distributed species occupying a narrow niche.Many other features of Offadesma, notably the structure of the ligament and shell clearlyally it and the Periplomatidae with the Laternulidae and the Thraciidae in a separate line of evolution from the other families of the Pandoracea, and probably deserving of super‐family status—the Thraciacea Stoliczka 1870.
Zonation and distribution of the beach mysid, Gastrosaccus psammodytes (Crustacea: Mysidacea)
Authors: Wooldridge T. 
Published: August 2009

AbstractDuring the day the sand burrowing mysid Gastrosaccus psammodytes is confined to the intertidal and surf zone. There is a clear pattern of intraspecific zonation with adult males, immatures and juveniles furthest offshore. Females move progressively inshore as the brood develops, with young‐bearing females occupying a zone closest inshore. At night G. psammodytes is present in the plankton when part of the population moves into deeper water and away from the area occupied during the day. Zonation appears to be related to the degree of planktonic activity. Loss or mortality of developing embryos is high in G. psammodytes and inshore movement of brooding females is interpreted as a movement away from excessive turbulence and sand movement in the area of breaking waves.
Life‐cycle and feeding strategies of freshwater triclads: a synthesis
Authors: Calow P. , Davidson A. F. , Woollhead A. S. 
Published: August 2009

AbsractA relationship is discovered between feeding and life‐cycle strategies in triclads which explains why closely related and coexisting species may either be semelparous (annual) or iteroparous (perennial). Semelparous species feed on active food and in so doing adopt a sit and wait feeding strategy whereas iteroparous species feed on sluggish food and have to seek it out. The semelparous species therefore tend, because of their lower metabolic costs in foraging, to be more efficient converters of food to tissue than the iteroparous species. This efficiency, which allows more rapid growth rates and some immunity to disturbances in food supply, means that in the field semelparous juveniles are likely to have better survival chances (relative to parents) than iteroparous juveniles. Hence sit and wait feeders can “afford” to invest more in reproduction and usually have more to invest than seek‐out feeders.
Further observations on the development and destruction of lamprey blood cells
Authors: Percy Lord Richard , Potter I. C. 
Published: August 2009

AbstractSupravital preparations of blood and haemopoietic tissues have been studied by interference contrast, phase contrast and conventional light microscopy to help identify the different categories of the smaller blood cells of lampreys. These methods were also used in conjunction with an examination of sectioned material and fixed blood films, to investigate macrophage activity by the blood cells and the liver Kupffer cells. The diameter of the smallest living blood cells was 4–5 |mUm. When these produced extensive clotting fibres, particularly in the presence of foreign substances, they were obviously thrombocytes, whereas others, some of which contained prominent nucleoli, were considered to represent small lymphocytes and stem cells. Slightly larger cells (5–6 |mUm), in which the nuclearcytoplasmic ratio was slightly lower and granules were being formed, represented the first stage in the formation of neutrophilic and eosinophilic granulocytes. The early members of the erythrocyte lineage could be distinguished from these early progranulocytes by their greater thickness under interference contrast microscopy and by their much more rapid degeneration and lack of amoeboid movement in blood films. All blood cells, apart from erythrocytes and differentiating cells of the erythrocyte series, showed amoeboid movement and many were capable of phagocytosing small particles. There was no evidence that, except for macrophages derived from lymphocyte‐like cells, any free blood cells were capable of engulfing whole erythrocytes. During metamorphosis, phagocytic activity was very conspicuous in both blood cells and Kupffer cells, the latter of which exhibited pronouncedn erythrophagocytosis.
Studies on the distribution, food, breeding biology and relative abundance of the Pygmy and Common shrews (Sorex minutus andS. araneus) in upland areas of northern Engl and.
Authors: Butterfield Jennifer , Coulson J. C. , Wanless Sarah 
Published: August 2009

The distribution and relative abundance of the Pygmy and Common shrews were investigated over two years at 42 sites across northern England and at a further seven sites in one year. Most of the sites were in upland areas above 250m in altitude. At almost all sites, the Pygmy shrew was more abundant than the Common shrew, often by a considerableA correlation exists between the numbers of shrews captured at a site and the abundance of invertebrates revealed by pitfall trapping. I t is recorded that Common shrews fed on earthworms (which are almost completely absent on peatlands) whilst Pygmy shrews did
Observations on the rhinoceros cardiac receptor system
Authors: Cave A. J. E. 
Published: August 2009

First‐time observations are submitted on the anatomy of the rhinoceros cardiac receptor apparatus. This is shown to comprise chemoreceptors in the form of canonical aortic and carotid glomera and mechanoreceptor areas essentially similar to those established for certain other mammalian forms. A description is given of the cardiac adventitial nerves(aortic nerves) which provide a guide to receptor areas. The structure of the rhinoceros aortic glomus is detailed.
A note on the mandible length of Red deer, Cervus elaphus, from Lyme Park, England
Authors: Goldspink C. R. 
Published: August 2009

The relationship between mandible length and body weight of a small population of Red deer in Lyme Park, Cheshire, is described. The mandibles are the largest so far recordedFrom the British Isles which is further evidence for a N‐S gradient in this character. Stags have smaller mandibles than hinds, an anomally which may be an adaptive consequence of their higher growth rate and larger body size.
The histochemistry and ultrastructure of the glandular vas deferens of Tubifex tubifex (Annelida: Oligochaeta)
Authors: Fleming T. P. 
Published: August 2009

The ultrastructure and histochemistry of the atrium, prostate gland and penis of Tubifex tubifex are described. The prostate gland, which forms a discrete structure alongside the atrium, consists of club‐shaped gland cells with narrow cell processes that converge onto the junction with the atrium, Prostate perikarya contain abundant rough endoplasmic reticulum (rER) and active Golgi cisternae and function in the synthesis of secretion granules. Prostate cell processes, characterized by a peripheral band of microtubules linked to an electron lucent cisterna derived from the perikaryon rER, penetrate the atrium and ramify between the atrial epithelium and musculature. The atrial epithelium consists of interstitial ciliated cells and anucleate glandular clements packed with secretion granules. Prostate cell processes ultimately open into the bases of the atrial glandular elements which therefore constitute the expanded apices of prostate cells. The morphological differentiation of prostate atrial gland cells into distinct zones concerned with the production, translocation and storage of secretion granules is discussed in relation to sperm transmission. The presence of a conventional peritoneum surrounding the prostate gland indicates that the gland cells originate from the atrial epithelium.The prostate‐atrial gland cells are of two types characterized by the ultrastructure and histochemistry of their secretion granules. Type I granules are uniformly electron dense and are composed of neutral mucopolysaccharide with vic glycol groups and basic protein containing tyrosine, tryptophan and cystine. Type I1 granules are heterogeneous and consist of electron dense subunits of basic protein within a microfibrillate matrix composed of carboxylated acid mucopolysaccharide. The possible function of prostatic secretion is discussed.The penis is composed of a simple tubular extension of the epithelial, muscular and peritoneal cells of the male duct‐body wall junction and is enclosed within a double foldin the epidermis. The penis lumen is plugged by secretion derived from the prostate‐atrial gland cells.
Locomotor behaviour of the walrus (Odobenus)
Authors: Gordon Kenneth R. 
Published: August 2009

The aquatic and terrestrial locomotion of the walrus are described using the frame‐by‐frame analysis of 16 mm cine film and the manipulation of bone‐muscle preparations. Thehind limbs of the walrus are the major source of aquatic propulsion; the forelimbs are used for manoeuvring as well as for propulsion.
An analysis of canine size and jaw shape in some Old and New World non‐human primates
Authors: Lucas P. W. 
Published: August 2009

An analysis of the relationship between the height of canine teeth, the length of the jaw and the height of the jaw joint above the occlusal plane was undertaken in catarrhine primates and some cebids. An inverse relationship was found in males between the anglethe jaw must be opened to clear the canine teeth and the height of the jaw joint above the occlusal plane, divided by the length of the lower jaw. A theoretical model is presented which can account for this phenomenon and which presumes selection pressure for alignment of the canine teeth when in use. In females, the angle the jaw must be opened to clearthe canine teeth was in most cases very small though in certain species elongated canineswere found.
Predation by Tawny owls (Strix aluco) on Bank voles (Clethrionomys glareolus) and Wood mice (Apodemus sylvaticus)
Authors: Southern H. N. , Lowe V. P. W. 
Published: August 2009

During 1954–56 we made a study of the numerical relationships between a population of Tawny owls (Strix aluco) and populations of their main prey species, the Bank vole (Clethrionomys glareolus) and the Wood mouse (Apodemus sylvaticus), in a 48.6‐ha area of mainly deciduous woodland near Oxford. The owls were censused by plotting their territorial challenges (hooting), the rodents by the capture‐mark‐recapture technique. Since the rodents were marked with numbered monel metal leg rings, we were able to recover a proportion of these in the pellets of undigested material cast by the owls.The results for Bank voles, which were the more numerous of the two prey species, indicated that 20–30% of the standing crop was removed by owls in any two‐month period. We also made an independent estimate of predation rate from the number of rings recovered from owl pellets in relation to the number of ringed rodents released into the population each two months. This coincided with the limits indicated by the first method for voles (20‐30% removed of the standing crop each 2 months).Wood mice were scarcer than Bank voles and were not amenable to satisfactory capturemark‐recapture analysis but, when treated on the system of recovery of rings in owl pellets, we found that they were preyed upon relatively more heavily than were the voles. Of the latter 18–46% of the marked animals were recovered in the owl pellets compared with 28–70% of the marked mice. Either the mice were preferred prey or they were more vulnerable to owl predation by reason of their preference for more open habitats.
Patterns of breeding behaviour and plasma levels of hormones in a free‐living population of Pied flycatchers,Ficedula hypoleuca
Authors: Silverin Bengt , Wingfield John C. 
Published: August 2009

Plasma levels of luteinizing hormone (LH) and steroid hormones were measured by radioimmunoassay in a series of plasma samples collected from a free‐living population of Pied flycatchers,Ficedula hypoleuca.Both males and females have similar circulating levels of LH and testosterone when they arrive in the breeding area. However, as territories and pair bonds are established, and as courtship and nest‐building ensue, the plasma levels of testosterone in males become elevated over those of females, although a lesser peak also occurs in females. As the egg laying phase and incubation begin, plasma levels of LH and testosterone decline sharply in both sexes. On the other hand polyterritorial males, that establish secondary territories, maintain higher levels of LH and testosterone than males remaining in the home‐territory, at least until they return to the home‐territory, usually at the middle part of the incubation period. By this time polyterritorial males also have basal levels of these hormones. Curiously, females on home‐territories show a small, but significant, rise of circulating LH and testosterone at the time the males return.In males, plasma levels of corticosterone are elevated from the time of arrival on the breeding grounds until the end of the nest‐building period. Thereafter corticosterone levels decline in males staying on the home‐territory but remain elevated in polyterritorial males until the latter return to the home‐territory. In contrast, circulating levels of corticosterone in females are only elevated for brief period during egg laying.
Hormone induced chromatophore changes in the European tree frog, Hyla arborea, in vitro
Authors: Nielsen Hans Ingolf , Bereiter‐Hahn Jürgen 
Published: August 2009

The colours of the European tree frog,Hvlu urhorea, depend on three types of chromatophores: in dermo‐epidermal direction melanophores, iridophores, and xanthophores. The ability ofthis species to assume a wide range ofcolours implies that very extensive changes in the chromatophores take place, which in turn require control by several regulating factors. The responses of the different chromatophore types to hormones with known melanophore‐affecting abilities (α‐MSH, β‐MSH, ACTH, melatonin) were tested in an in vitro system (freshly explanted skin) using reflectance microspectrophotometry, light microscopy and time‐lapse cinemicrography.α‐MSH, β‐MSH and ACTH all induce a rapid dispersion of melanosomes during the 10 min after addition. The degree of pigment dispersion induced by ACTH is slightly less than after stimulation with α‐MSH or β‐MSH.The iridophores react to MSH or ACTH treatment with a contraction of the entire cell (causing a reduction in reflecting area), and a change in orientation of the platelets, causing a decrease in selective reflectance. The iridophores appear to be especially sensitive to ACTH. A very striking feature of the iridophores when studied with time‐lapse cinematography is their strong pulsations (approx. once per minute).The xanthophores react to MSH and ACTH with a contraction. These cells appear to be sensitive to β‐MSH in particular.Melatonin strongly counteracts the effects of α‐MSH, β‐MSH and ACTH on all chromatophores.These studies confirm the dynamic nature not only of the melanophores, but also of the iridophores and xanthophores, as pointed out by Schmidt (1920) and Nielsen (1978a). Furthermore the differences in the time course of the stimulation of the different types of chromatophores by various hormones may provide an experimental basis for the explanation of colour changes in Hyfa arboreu.
The dynamics and regulation of small rodent populations in the woodland ecosystems of Killarney, Ireland
Authors: Smal C. M. , Fairley J. S. 
Published: August 2009

Populations of Wood mice Apodemus sylvaticus and Bank voles Clelhrionomys glareolus were studied by mark‐recapture techniques in five different woodlands but concentrated on an oak Quercus petraea wood and a yew Taxus baccata wood, where food supply was also investigated. Much of the yew wood was on limestone pavement which was greatly creviced thus providing static and quantifiable cover. Indices of the intensity with which food was being searched for were obtained on all areas by seed‐removal experiments.Trappability varied within the populations and seasonally, being highest in summer. Unusually high densities of mice were recorded in the yew wood but not elsewhere; vole densities were always low. There was an inverse relationship between range length and density: mean range length in the yew wood was exceptionally low. Males generally ranged further than females, voles further than mice. Females outnumbered males in the oak wood, where cover was minimal, when the population was low. In the two areas with most cover, males outnumbered females. In a further area, where numbers were initially exceedingly low, the population consisted entirely of males for almost a year. Sexes differed in habitat preference but numbers, especially of males, were significantly correlated with cover. Voles usually bred for shorter periods than mice. Overwinter breeding and increased overwinter survival followed good seed years. Individuals recruited when food was plentiful lived longest. In seed‐removal experiments rate of removal increased with shortage of natural seed.Food and intraspecific aggression were the probable major factors in regulating population size, of mice at least. Cover probably modifies intrinsic mechanisms by reducing numbers of encounters between individuals.