摘要:

Leptopelis hyloidesandChiromantis rufescens,which deposit eggs out of water, are compared with the aquatic breedingBufo maculatusin terms of the ability of their larvae to move on land.Leptopelis larvaetravelled further, faster and in a more consistent direction thanChiromantislarvae; they also survived better on land.Bufolarvae showed no terrestrial locomotion. These facts are related to the breeding behaviour of the three species. Locomotory ability in bothLeptopelisandChiromantislarvae was influenced by relative humidity and inLeptopelisthe direction of movement was apparently influenced by topographic gradient and by the position of the closest standing water.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03243.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Bioluminescence is reported from the evermannellid fishCoccorella atrata(Alcock). Light is emitted ventrally from three regions of the intestine and along the length of the pyloric caecum. The structure of the mucosal epithelium in these regions is described.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03244.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Studies on the ellipsoid erythroblasts of Llama, L a m gluma, L. during erythropoiesis showed the appearance of the marginal band composed of approximately 29 microtubules. As the maturation of erythrocytes goes on, the number of marginal band microtubules diminishes. No microtubules were found in mature erythrocytes of Llama.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03245.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Pileolaria levensteinaesp. nov. was represented by juvenile and presumably adult stages, attached to ferromanganese substrata. None bore embryos, but the larger individuals had deep opercular cups and the species is closely related to certain shallow water forms which incubate in such cups. A second species was dextrally coiling but represented by a single fragment too small to describe. Spirorbids would appear to be preadapted for abyssal life, by having a brief, lecithotrophic larval stage.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03246.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The light cues received by the larvae ofPieris brassicaewhich determine diapause can also influence the carotenoid distribution (and hence the colour) in the epidermis and cuticle of the diapausing pupae. Irrespective of background or light cues received during the “sensitive period” of the pharate pupa, these diapausing pupae are coloured green. They then contain more than double the concentration of carotenoids in their epidermis than the non‐diapausing pupae. This green colour can be somewhat modified by switching the full grown larvae to long day regimes immediately after feeding ceases.The Large White and Small White butterfly each has a characteristic carotenoid storage pattern, which can be demonstrated by feeding the larvae on portions of the same cabbage leaves. The braconid parasiteApanteles glomeratusmirrors the carotenoids in its

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03247.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A routine was established for sampling pH in aquatic environments which permitted assessment of an “average site pH”±0.5 units by measuring that of a single sample at any time of year. Requisites for accuracy were that samples should be taken in clear water away from weed, and at least three days after significant rainfall.pH measurements were taken in a number of ponds and compared with the use of these waters for breeding purposes by Common toads(Bufo bufo)and frogs(Rana lemporaria).Toads were found breeding in water slightly more acid than those tolerated by frogs. Similar measurements of pond pH in dune and heath habitats frequented by Natterjack toads(Bufo calamita)were compared with breeding site choices by these anurans. A marked avoidance of acid waters was evident in the predominantly acid heathland habitats. This was probably not directly related to the concentrations of inorganic ions in the pools.Development ofRana lemporaria, Bufo bufoandB. calamitaspawn under various pH conditions was examined. Survival rates were optimal in the pH ranges found to be chosen in the wild, and no differences were observed betweenBufo calamitaspawn taken from dune or heathland populations. Developmental abnormalities in the tadpoles were more frequent under acid conditions.A preliminary study of ponds used by the three species of anurans native to Britain was carried out by measuring pH with a tested field procedure. Differences betweenBufo bufoandRana temporariabreeding sites were not significant on the basis of pH in the areas studied, butB. calamitapopulations on heathland were found to avoid the acid pools. The field data correlated well with the pH tolerance of the anuran larvae reared in captivity. The significance of these findings is discussed.The authors wish to thank Dr A. Cooke (Institute of Terrestrial Ecology) and Dr D. Sutcliffe (Freshwater Biological Association) for analyses of selected water samples; Mrs M. Beebee for statistical treatment of the data; and the Carnegie (U.K.) Trust for financial sup

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03248.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Cineradiographic analysis of the posture and movements of the femur and pelvis in representatives of three carnivore families (Procyonidae, Felidae, Canidae) reveals discrete locomotor patterns during walking. Raccoons (Procyon tolor) abduct the femur substantially, and engender large pelvic movements. Canids (Vulpes fulva, Canis familiaris) abduct the femur slightly, whereas cats (Felis domestica) employ only a sagittal excursion of the femur with the least pelvic oscillation. Casted replicas of the femora and pelves of these species, fixed in the various characteristic postures and then sectioned, demonstrate differences in articular relationships. The depth of the acetabulum, location of the fovea capitis femoris, and configuration of the articular surface on the femoral head vary by species according to the femoral posture and excursions employed in locomotion and other activities. Three patterns of locomotor adaptation are identified on the basis of these data and behavioural observations. Ambulatory carnivores (e.g. raccoons) are adapted for a wide range of femoral postures, and particularly for abduction used in climbing. In contrast, cursorial carnivores are specialized for a narrower range of hindlimb movements. The canine pattern is the most restricted; the hip structure accommodates little more than the modest degree of abduction employed in terrestrial locomotion. The feline pattern, although characterized by the most adducted limb posture during walking, nonetheless retains structural adaptations for a wider range of femoral postures than in canines which may be employed in climbing and in predatory activities. The habits of certain fossil carnivores are interpreted on the basis of these patterns. Creodonts and a Paleocene miacid (Carnivora) show distinctly ambulatory adaptations, whereas later miacids developed various cursorial characters. The early Oligocene canid Hesperocyon gregarius had a hip structure with features comparable to those in modern felids and canids.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03249.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Background choice experiments were performed using polymorphic night flying moths common in Britain and emerging at different times of the year. Such species have to spend their daylight hours motionless at rest on their correct backgrounds. Significant differences were found between the site preferences of different morphs of the same species. The morphs chose backgrounds most appropriate to their colouration.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03250.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The hairpencils of the Mediterranean flour moth,Ephestia kuehniellaZeller, are tufts of modified scales between the seventh and eighth abdominal segments of the adult males. The fine structure and development of a hairpencil organule is described. A process of the trichogen cell secretes the modified scale and then withdraws, and the cell invaginates forming a microvillous lumen into which pheromone is probably secreted. This lumen communicates with the outside via rows of pores in the hollow scale. The opening of these pores when the moth emerges from the pupal cuticle may be a result of the drying out of the membrane that covered them. The socket of the hairpencil scale is secreted by a tormogen cell.The hairpencils of male Lepidoptera differ in position from family to family, but the organules that compose them seem to share a common structure. Epidermal glands and organules are classified in a scheme that takes account of their mode of development.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03251.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The melanic and typical morphs from 13 families of the moth,Allophyes oxyacanthae(Linnaeus) were tested for evidence of resting site selection in a large box lined with oak bark of three reflectances. For 12 of the families, one or both of the parents originated from two families, 0/1 and 0/3, which had been tested in a similar manner in the previous year. In all of these 12 families typicals showed a preference for the palest background available, “light grey”. The melanic results for the same families were significantly heterogeneous but could be partitioned on the basis of parentage, into six families in which melanics preferred light grey, and six families in which melanics preferred the background on which they are most cryptic, dark grey. In the only family in which neither of the parents originated from either 0/1 or 0/3, both typical and melanics showed a preference for the background on which typicals are most cryptic, bare bark. The results of the two years' experiments indicate that it is necessary to postulate that, in addition to the pleiotropic effects of alleles at the melanic locus, another locus (or loci) is involved in the control of resting site select

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1977.tb03252.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY