摘要:

Histological and histochemical methods have been used to study feeding, digestion and food storage in two species of temnocephalid flatworms.Temnocephala brenesi, from Costa Rica, andT. novae‐zealandiae, from New Zealand, are ectocommensal on the gills of freshwater decapod crustaceans and feed on a variety of small aquatic organisms. The prey is captured by means of prehensile tentacles, and is either ingested intact or held to the mouth whilst the pharynx ruptures the integument to draw in the body contents.In both species the alimentary system is of the typical rhabdocoel form, with a doliiform pharynx and saccate intestine. The gastrodermis is differentiated into glandular and phagocytic components, with some of the gland cells subgastrodermal and embedded in the parenchyma surrounding the intestine.Digestion occurs by a combination of extra‐ and intracellular processes; endo‐ and exopeptidases, acid and alkaline phosphatases and lipases are secreted in sequence and can be demonstrated histochemically.Deposits of fat occur in the vitellaria and eggs, and glycogen is laid down in the testes and the musculature of the pharynx and sucker.The ectocommensal life has not caused any significant change in the general pattern of nutrition characteristic of free‐living flatworms and no tendency towards a parasitic existence has bee

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08574.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The intestine of the parasitic nematodeAspiculuris tetrapterahas been shown to undergo periodic contractions which suggested that muscles were associated with the intestine. Examination of sections of the intestine has shown that the intestinal cells are similar to those of other nematodes which have been described at the ultra‐structural level but there is a network of muscle fibres around the whole of the intestine. There are many virus‐like particles in the epithelial cells; yeast‐like micro‐organisms in the lumen of the intestine are attached to the apical surface of the epithelial cells and they replace some of the microvilli. The part played by the muscle network during digestion and defecation is di

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08575.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

A study in Dorset, England, of a very large nursing colony of the common batPipistrellus pipistrellusprovided some much needed basic taxonomic data for this species in the British Isles. Despite the fact that 389 of 429 bats caught were juveniles the measurements were demonstrated to be comparable to adults. The sex ratio of juveniles were shown to be 1:1. No adult males were caught. Amongst the 40 adult females, eight were nulliparous (never having had young) and the remainder had all given birth and were lactating or just post lactating. It appeared that at least somePipistrellusdo not become pregnant in their first year. It was estimated that this colony consumed a minimum of 100 kg of flying insects during July and August.The individuals tend to be 0·5 g heavier one year after weaning and a further 0·5 g heavier the following year.Adult females leave the nursery roost immediately after weaning and it was suggested that this may be to prevent competing for food with the juveniles.Behaviour in roost, upon emergence and in captivity is describe

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08576.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

A new cymothoid isopod which parasitizes clupeid fishes in Lake Tanganyika is described. That this species is a protandrous hermaphrodite is demonstrated. There are also indications that transformation from the male to the female phase may occur at different stages of development in different individuals.Two isopods with distinctly marine affinities are now known from Lake Tanganyika but it is not certain that they are derived from a common ancestor. The marine‐like facies of the Lake Tanganyika fauna is therefore enhanced but, although no proven explanation of the facts of distribution can be given, Moore's theory that the lake is a remnant of an ancient sea is not revive

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08577.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The known distribution of the parasitic crustaceans of African freshwater fishes, which now include some 80 more or less adequately described taxa, is summarized, and the significance of some of the patterns which they exhibit is discussed. Information is given on the taxonomy biology and evolution of certain species.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08578.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Olfaction has been largely overlooked as a factor in avian ethology. Olfactory structure in 13 species of Rallidae (Gruiformes) and in a distant terrestrial ordinal relative, the button‐quail,Turnix, is described. The design of the nasal fossa for the efficient function of the olfactory membrane is reviewed. Rallidae have an average olfactory bulb‐to‐hemisphere ratio of 23%, about the middle of the scale of relative olfactory ratios in birds. The ratio inTurnixis 12·5%. While there is no significant difference in the amount of olfactory equipment in either dispersed or overlapping species of Rallidae, evidence is presented that there are qualitative differences in secretory cells in the olfactory and lateral nasal gland systems. It is suggested that these may influence the reception or inhibition of particular od

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08579.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The neurosecretory system of the earthworm,Pheretima posthuma, has been studied by PF, PATh and PAVB bulk‐stained preparations and sections. There are three types (a, bandc) of neurosecretory cells in the cerebral ganglion, suboesophageal ganglion and the nerve cord ganglia. Axons ofa‐ andb‐cells are observedin totoin the cerebral and the suboesophageal ganglions. The axons are short and their axonal ends are bulb‐like. While the axons of the neurosecretory cells of the cerebral ganglion remain directed ventrally, those of the suboesophageal ganglion converge in a small area. This area has been considered as the neurohaemal organ, but of an elementary type.In the cerebral ganglionb‐cells exhibit a vacuolated cytoplasm. Vacuoles of varying size and number have been observed in those cells whose perikarya are loaded heavily with NSM. The vacuoles and the associated neurosecretory material extrude from the cell after rupturing the cell wall and the released material, associated with the vacuoles, is observed in the form of discrete bodies between the neurosecretory cells. After traversing the intercellular spaces the NSM accumulates on the ventral surface of the cerebral ganglion and some material is found to extend towards the suboesophageal ganglion, via the circumoesophageal connectives. It is suggested that a part of the NSM is absorbed into the blood vessels in the region of the cerebral ganglion and the remainder in the region of the suboesophageal ganglion; but the mechanism by which the liberated material is absorbed in the blood has not been determined. Thus inPheretimathere are two neurosecretory pathways—intracellular and intercellular—for the transportation of NSM elaborated by t

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08580.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The reproductive physiology of 156 feral and 31 captive specimens of two eastern subspecies of the Spotted skunk (Spilogale putorius) was studied, the histology of the primary and secondary sexual organs of both sexes described, and the breeding cycle outlined.Most matings take place in April and parturition occurs in June. Some females from southern latitudes may produce two litters in a single year.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1968.tb08581.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY