摘要:

Four species were collected, all attached to marine angiosperms,Pileolaria daijonesisp.n. being the most abundant. The other three have the collar folds fused dorsally, as is characteristic ofDexiospira(=NeodexiospiraPillai), which is here regarded as a subgenus ofJanua. Janua (Dexiospira) formosa(Bush) andJanua (Dexiospira) steueriSterzinger are distinguished clearly from one another for the first time and shown to be widely distributed in warm seas.Janua (Fauveldora) kayisubgen. et sp. n.is a very closely related sinistral form, which extends to the Persian Gulf and Ceylon.Reviewing serpulids, it seems that the primitive position of the operculum in Serpulinae and Spirorbinae was sinistral. The most recent changes involving this character, however, have beensitus inversusback‐mutations, from stocks which are dextral and presumably more labile.Summary:Four species from Kenya were all opercular incubators and attached to marine angiosperms,Pileolaria daijonesisp.n.being much the most numerous. The other three all have the collar folds fused dorsally, but should be placed in the redefined genusJanua, two falling indisputably into the redefined subgenusDexiospira(=NeodexiospiraPillai). These two,J. (D.) formosaBush andJ. (D.) steueriSterzinger, are redescribed and distinguished clearly from one another for the first time, the easiest distinction being that the blades of the abdominal setae are broad in the former and narrow in the latter. Both are shown to be widely distributed in warm seas. The remaining species,Janua (Fauveldora) kayisubgen. et sp.n., which extends to the Persian Gulf and Ceylon, is closely related toDexiospira, but its operculum and related coiling are sinistral. Reviewing these characters in serpulids generally, it seems clear that the primitive position of the operculum in Serpulinae and Spirorbinae was sinistral, that many Spirorbinae have become dextral and that the most recent evolutionary changes, involving this character, have been back‐mutations from such dextral sto

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04071.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The weights and lengths of about a thousand individuals ofSteganacarus magnus(Nic.) have been analysed and found to have a bimodal distribution. It is suggested that this can be used as an aid to separating the sexes in this species.Summary:An analysis of the weight distributions of adultSteganacarus magnus(Nic.) showed them to be bimodal. Small individuals, without eggs and pre‐larvae had a mean weight of 159 μg and large individuals with eggs and pre‐larvae had a mean weight of 335 μg. It is suggested that these two weight classes represent male and female indivi

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04072.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The aim of this work was to identify behavioural differences between the domesticated ferretMustela furoand its wild counterpart the European polecatM. putoriusand to obtain objective measures of one or more of these differences.The animals used in this study were tameM. putorius, M. furo, wild caught hybrids and laboratory reared F1hybrids between the two species.Ferrets differed in their behaviour in unfamiliar environments and in the fact that they do not develop fear of man. The F1hybrids resembledM. putoriusin that they develop a fear of man if left with their mother during a critical period between 7½ and 8½ weeks of age. The phenomenon of imprinting may be involved in this developmental process.The attention response to a rustling noise was investigated under controlled conditions revealing differences in response decrement between the four types of polecat.M. putoriusand the hybrids habituated more rapidly to the sound than did the ferrets.The results obtained for F1hybrids depended upon the previous environmental history of the individual. Those individuals which had been living in outdoor cages responded differently from the ones in indoor cages. The hypothesis was put forward that the hybrids respond more frequently if the experimental situation provides a greater contrast with their normal environment and that the individual's response threshold is therefore “set” to specific environmental conditions.The results obtained agree with the hypothesis first put forward by Lorenz (1953) that the behaviour of domesticated animals resembles that of juvenile individuals of their wild counterpart.Summary:A comparison is made between the behaviour of European polecats (Mustela putorius), the domesticated ferret (M. furo) and hybrids between the two species.Differences were found in exploratory behaviour, fear of man and the frequency of occurrence of the “attention response”.The occurrence of the “attention response” was studied under controlled conditions. It was found, on playing the rustling sound 40 times at minute intervals, that this sound elicited the attention response for longer in ferrets than in European polecats and hybrids between the two species. The most rapid habituation occurred in polecats, the F1hybrids being intermediate in their response betweenM. putoriusandM. furo.The results obtained for the F1hybrids were influenced by the conditions under which the animals were previously caged.The results appear to support Lorenz' view that domesticated animals show juvenility in their behaviour as compared with their wild

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04073.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The morphology and histology of the alimentary canal of the rock chitonAcanthopleura spinigeraare described and the ability of regions of the gut to digest specific substrates investigated. The oesophagus is produced into a pair of thin‐walled lateral pouches, the salivary glands or “sugar glands” which empty into the stomach. Folds of the capacious stomach are almost obscured by the large digestive gland over which is coiled the intestine. Histologically the gut consists of an outer layer of connective tissue, an inner muscular layer and a ciliated epithelium which varies in thickness from one region to the next. Proteases are most active in the stomach, digestive gland and anterior intestine at pH 6·5 and in the posterior intestine at pH 7·5‐8·5. The digestion of lipoidal substance was greatest in the stomach and digestive gland and least in anterior intestine. There was little increase in the amount of digestion product obtained after 20 hours incubation. All regions of the alimentary canal and salivary gland were capable of digesting carbohydrates except that many low molecular weight carbohydrates were digested by salivary gland extracts only. The amylases were most active at pH 6–6·5. It is concluded that digestive enzymes are distributed throughout the intestinal tract but the amount of enzyme present varies from region to region, and is greatest just

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04074.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The lateral scent organs ofArvicola terrestris(L.) are basically similar in construction to those ofA. scherman(Shaw), and differ in that they do not express long cylinders of secretion at the end of the breeding season, and that frequent epidermal vesicles are observed. During the year the organ of the male undergoes a cycle of activity with a peak in secretory activity shortly following the peak in the cycle of testis weight. Bilateral castration causes a marked involution of the organ in the male, which can be reconstituted by the administration of exogenous testosterone.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04075.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The burrows ofFungiacavain the skeleton of living fungid corals are initially superficial and peripheral, later they become deep; they always open into the coelenteron. Boring is exclusively chemical, possibly by secretion of a calcium‐chelating mucus by the epithelium of the pallial envelope, which surrounds the excessively delicate shell, and of the siphons. These epithelia also secrete aragonite with which all cavities in the corralum are filled and the presence of which reveals the track of the bivalve through the corallum. By the dual operation of resorption and secretion,Fungiacavaalways precisely fills the cavity it occupies. There is no reaction by the coral to the presence of the symbiont.Summary:The burrows ofFungiacava eilatensiswithin the skeleton of livingFungia scutariaare described.Burrows of young individuals are superficial, those of older ones are deep. They open respectively into peripheral and central regions of the coelenteron.Burrows change in shape from an ovoid to a dorso‐ventrally flattened heart‐shape with alteration in form of the bivalve.In view of the extreme delicacy of the shell and its complete enclosure within a pallial envelope, burrowing must be exclusively chemical, possibly by secretion of a calcium‐chelating mucus.The pallial envelope is ciliated and covered with a dendritic system of shallow grooves converging on the pallial gape. This may possibly assist in either application of secretion or removal of the products of resorption, or both.The burrow is enlarged but also altered in shape by selective resorption and secretion of aragonite—which fills in all trabecular spaces in the coral skeleton penetrated by the burrows—by the outer epithelia of the pallial envelope and the siphons.Movement ofFungiacavathrough the coral skeleton is clearly revealed by the presence of homogeneous aragonite deposits.There is no trace of reaction by the coral to the presence of the bivalve.Without knowledge of the life history, it is impossible to determine whether the initial superficial chambers are due to a possible initial tube secretion by the bivalve or to a reaction at this stage of the coral to the presence of the newly se

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04076.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The occurrence of helminth parasites and leptospires from the Long‐tailed field mouse,Apodemus sylvaticus, the Bank vole,Clethrionomys giareolusand the Short‐tailed vole,Microtus agrestishas been studied from four woodland areas in Surrey. The composition of the helminth fauna of these rodents, particularlyA. sylvaticusandC. giareolus, differs from that of previous studies carried out in the British Isles in consisting largely of cestodes and fewer species of digeneans and nematodes. On the other hand the degree of infection of the rodents with nematodes as in the case ofA. sylvaticusinfected with the trichostrongylidNematospiroides dubiusand theoxyuridSyphacia stromaand ofC. giareoluswith thecap‐illaridCapillaria muris sylvaticiis greater than the cestode and digenean infections and is probably linked with the monoxenous nature of the nematode life cycles.Differences in the number, incidence and degree of infection of mice and voles with species of helminths is undoubtedly linked with differences in the feeding habits of the respective hosts but the present study has also confirmed that infection levels in both leptospires and helminths are influenced by the age/sex relationships of the host together with season and habitat. The relationship between the distribution of rodents infected with leptospires and some helminths suggests similarities in the mode of their transmi

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04077.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Pseudopythina subsinuata(Lischke) has been found in Hong Kong waters to be commensally associated with the following stomatopod crustaceans:Oratosquilla perpensa(Kemp),Oratosquilla interrupta(Kemp),Oratosquilla oratorio(De Haan),Harpiosquilla japonicaManning. The location on the host is highly specific.Studies on the functional morphology and biology of this bivalve have shown that it is relatively unspecialized except with regard to its sexual cycle. It has been shown to be a protandric hermaphrodite in which a smaller male normally occurs in close association with a larger female. Fertilization occurs in the supra‐branchial chamber of the female and the young are subsequently incubated in the same position. Solitary females also occur.It is suggested that a complex sexual cycle was a prerequisite for the successful exploitation of the commensal mode of life by the Leptonacea in general and that subsequent morphological specializations have occurred in only some.Summary:Pseudopythina subsinuatahas been found in Hong Kong waters living commensally on the following species of stomatopod crustaceans:Oratosquilla perpensa(Kemp),Oratosquilla interrupta(Kemp),Oratosquilla oratorio(DeHaan), HarpiosquiliajaponicaManning.[ts location on the host is extremely specific and is occasioned by the requirements of the commensal and the limitations imposed by the behaviour of the host.Pseudopythina subsinuatapossesses many characters which suggest that it has only comparatively recently adopted a commensal mode of life:(1) It is not host specific.(2) It possesses a large shell with distinct hinge teeth.(3) The mantle edges are not reflected over the shell, and there is no inhalant siphon.(4) There is a well developed byssal apparatus.(5) The stomach is large, not reduced and non‐specialized.(6) The style sac still retains a connection with the mid‐gut along half its length.Some of these primitive characters, e.g. the large byssus, have been retained because they possess an obvious survival value. Other characters, e.g. the large labial palps, and the absence of interlamellar junctions in the ctenidia are probably specializations.The sexual cycle ofPseudopythina subsinuatais complex, the animal being a protandrous consecutive hermaphrodite. Solitary females also occur in the population. Fertilization occurs in the supra‐branchial chamber and the young are incubated there at least until the late veliger stage.It is suggested that a highly specialized sexual cycle was developed early in the evolution of the Leptonacea and was a prerequisite for the successful adoption of a commensal mode of life. Anatomical specializations evolved later, and to different degrees in different phyl

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04078.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Allometric growth of the postembryonic stages ofEctobius lapponicus(Linn.) andE. panzeriStephens is described and analysed. Alternative methods of computing the allometric growth equation are discussed and applied, with the necessary significance tests, to a large number of skeletal structures in all developmental stages of each sex. The validity of Dyar's Law and its modifications are assessed quantitatively.Summary:The growth in linear dimensions of 74 exosketetal structures has been studied quantitatively in all instars of both sexes ofEctobius lapponicusandE. panzeri.Almost all the investigated structures show some statistically significant degree of allometric growth, but relatively few of them grow by simple allometry. Some possible reasons for this are indicated.Well‐defined growth gradients exist in the appendages and along the main axis of the body. Allometric growth contours, showing sexual and specific differences, express the temporal and spatial variations in the allometric growth ratio.The limitations of Dyar's Law and Przibram's Rule are discussed and it is shown that conformity with Dyar's Law is not improved by allowing for differences in the duration of the instars.It is emphasized that allometric growth studies should involve the choice of a suitable reference dimension and the selection of an appropriate statistical model to which the growth data are fitted. The estimation of the allometry parameters a andb, as well as the appropriate significance tests, depend on the model chosen, though the two models compared in this study do not yield appreciably different estimate

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04079.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A preliminary investigation into the effect of wind on shore gastropods has been undertaken. Moderate winds displace someMonodonta lineata(da Costa) from boulders on the shore and some individuals detach within six hours in weaker winds in the laboratory (5–10 km/h, 10°C, 94% humidity). Sheltered aspects of the rock are used to minimize the effects of the wind on shores, and maintenance movements on the shore are extensive.Summary:In calm conditions and in light windsMonodonta lineatais more widely dispersed about the rocks than in moderate winds when the animals are either sheltering in cracks or displaced.Providing the rock surface is damp then animals continue to move about during emersion in light winds. On a small boulder beach animals moved as much as 4 m upshore during one tidal cycle. Only slight reorientation movements were recorded during moderate winds.Animals withstand a windspeed of 4 km/h for six hours in a wind tunnel in a humidity of 94% at 10°C, but are displaced within an hour by 10 km/h winds in similar conditi

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1972.tb04080.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY