摘要:

Estimates of body weight, group size, home range size, day range length, socionomic sex ratio and sexual dimorphism are compared between 100 primate species, allocated to seven ecological categories. As would be predicted on energetic grounds, home range size and day range length are positively related to group weight and are greater in frugivores than in folivores; population density is negatively related to body weight; and group size is positively related to body weight. The adaptive significance of Variation in body size, sexual dimorphism and socionomic sex ratio is also discussed.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04171.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

At a constant temperature and humidity there was a linear relationship between the log of survival time and the log of shell length inLymnaea tomentosaandL. columella.Reasons are suggested for this relationship. There was no significant species difference in ability to resist desiccation, provided specimens of either species were of similar shell‐lengt

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04172.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Comparative studies of melanism in the two cryptic moth species,Diurnea fagella(Denis&Schiffermüller) andAllophyes oxyacanthae(L.), have been carried out in southern England and south Wales. Estimates of the relative crypsis of the melanic and typical forms of both these species have been made at a number of sites and these were compared with the melanic frequencies in samples from these sites. These comparisons showed that selective prédation could be a major factor in the variation of melanic frequencies of both of these species. A consideration of the spread of melanism in these species suggests that non‐visual selection may favour the melanics ofD. fagellain urban areas and that non‐visual selection, not closely associated with urban conditions, may be responsible for the restriction of melanics inA. oxyacanthaeto Britain. The results for these two species are discussed in relation to investigations of melanism in other moth sp

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04173.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Fourteen species of gobies (Teleostei: Gobiidae), 12 of which were collected, were found living in association with seven “types” of alpheid prawn (Decapoda: Alpheidae) in the Seychelles, Western Indian Ocean. One new genus—Stonogobiops—and three new species—Stonogobiops dracula, Cryptocentrus auroraandC. wheeled—of prawn‐associated goby are described. Full descriptions of the new genus and species, and shorter descriptions of the remaining species, are given; the generaIotogobiusSmith andCryptocentropsSmith are synonymized withCryptocentrusEhrenberg. Aspects of the ecology of the prawn‐associated gobies were studied. Species specificity between gobies and prawns varied considerably. The species present exhibited a marked degree of habitat segregation, and there were differences between species in nearest‐neighbour burrow distances. A wide range of degrees of looseness of association between goby and prawn was also observed. The evolution of the symbiosis is discussed in the light of t

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04174.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A population of the intertidal isopodExcirolana braziliensiswas followed over a 10‐month period at Naos Island, Panama. Average intertidal density was 2147/m2with maximum abundance occurring in the highest level. Adults were present only in the highest tidal level. Juveniles were distributed throughout all tidal levels and comprised at least 70% of the population at all times. Mean size of individuals decreased from the highest level seaward. Reproductive females were present the year round. The number of young ranged from four to 17 per brood and was dependent on the length of the female. Adults were very tolerant of changes in temperature and salinit

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04175.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

An investigation has been made in both the parasitic lampreyLampetra fluviatilisand in its non‐parasitic derivativeLampetra planeriof the rate at which the fat column replaces the typhlosole and nephric fold as the principal site of haemopoiesis. In the typhlosole, blood cell formation started to decline prior to the onset of external metamorphosis and had ceased within four weeks of the commencement of transformation. In the nephric fold haemopoiesis continued for several weeks in the region where the larval opisthonephros persisted but was never observed in the newly developing adult kidney. Soon after the onset of external metamorphosis the fat column started to become haemopoietic and later became the main site of blood cell formation. The rate at which the haemopoietic function was transferred from the nephric fold and typhlosole to the fat column was greater inL. fluviatilisthan inL. planeri.Since a similar more rapid change inL. fluviatilishas also been found in the switch from larval to adult haemoglobin, the former type of haemoglobins may be produced only in erythrocytes originating in the nephric fold and typhlosole, whereas the latter type may be restricted to cells developed in the fat column. It is also suggested that the functional significance of the alteration in haemopoietic sites is related to changes at metamorphosis in the three regions where blood cell formation occur

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04176.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The principal bones, muscles and tendons in the legs of seven species of antelope of varying size have been measured, and aliometric equations have been derived. Some data published by Sachs (1967) have also been analysed. Most of the exponents of the aliometric equations agree well with McMahon's (1973, 1975a) theory of elastic similarity: lengths are approximately proportional to (mass)0˙25, diameters to (mass)0˙375and cross‐sectional areas to (mass)0˙75. However, some of the exponents for diameters and areas in the hind leg are significantly different from those predicted by the theory.The results are discussed in conjunction with previously published data on fast galloping. It is shown that maximum stresses in bones, muscles and tendons are probably more or less independent of body mass in antelopes galloping at their maximum speed. The tensile stresses in the tibia and humerus approach the tensile yield strength of bone. The total work which is done by the muscles in each stride at maximum speed and the energy saved by elastic storage are probably more or less proportional to body mass. The deviations of some of the allometric exponents for diameter from the expected value of 0middot;375 are partially expla

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb04177.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY