摘要:

The behaviour ofCorophium volutator(Pallas) is outlined. Swimming, crawling, burrowing and feeding activities are described in detail. Animals usually swim on their backs. Every few seconds, swimming alternates with passive sinking. Animals can crawl over surfaces in and out of water. Out of water they do so by a looping motion using their second antennae and telson. When out of water animals crawl away from light and down slopes. In water they swim towards light. Burrowing is initiated by rapid beating of the pleopods; the animal then sinks below the surface by a concerted action of pereiopods, pleopods, telson, uropods and second antennae; within a few minutes, a shallow burrow is formed. The formation of permanent burrows is dependant on particle size, on adhesive properties of detritus and primary films on sand particles, and on a secretion produced by the animal itself. Individuals can turn about in permanent burrows. The species is essentially a detritus feeder. Animals normally feed only when in their burrows, by using their second antennae to scrape material from the substrate surface into the entrance of the burrow. This material is then transported to the mouth by the feeding appendages and respiratory current. The behaviour of small and large animals differs; small animals burrow rapidly and permanently, and do not emerge spontaneously; furthermore, they only swim occasionally. Large animals swim more frequently, spend more time on the substrate surface, and periodically move burrows. It is suggested that new habitats are colonized by large animals which have already bred once.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03013.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

The frequency of reversal of the respiratory current is recorded forCancer pagurus, Macropipus puber, Corystes cassivelaunusandHomarus gammarusby cannulating the gill chamber and recording pressure changes therein. The predominant respiratory current flows backwards inCorystesand forwards in the other three, but all show rhythmic reversals of that current which appear to form an integral part of the mechanism of gill ventilation. Reversals appear to have significant gill cleaning functions only inHomarusandperhaps alsoCorystes.Measurements of gill ventilation volumes support these findings. Macropipus puber takes in almost all respiratory water at the bases of the chelae, anterior to the gills, and it shows a high reversal frequency apparently to irrigate the posterodorsal aspect of the gills. Cancer pagurus takes in a considerable volume of respiratory water at the bases of the last pair of peraeopods in addition to that entering at the bases of the chelae. This species shows fewer reversals, since the posterior gills are irrigated during normal forward flow, but artificial closure of the posterior openings results in an increased reversal rate.Comparisons are made of the gill ventilation patterns of all these species, together with Carcinus maenas described previously, and their functional inter‐relationships are discusse

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03014.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

A study of a selection of egg shells of the Falconiformes has been made similar to the earlier ones on ratites, the Anatidae and the Sphenisciformes. Chemical analyses, and histological and plastic embedding techniques were used.The main part of the shell in all species studied consists of large crystals running through the shell. There was no layer of fine vertical crystals above this and no cover, and even the cuticle was not very pronounced. Histological studies showed no major differences, except that some shells had vacuoles in the outer layers. All such shells also gave an unetched outer layer when plastic embedded radial sections were studied and thin sections showed spaces between and within crystals. These spaces in the outer layers of the shell were of taxonomic interest for they were not present in the Cathartidae, the Falconidae and Sagittarius serpentarius.Pore channels appeared to be much sparser than in other orders so far studied and all pores were single. Pigment was present on the surface of some shells, but it was also found in different layers of the shell right down to the cone layer and, in one case, had leaked through on to the membrane.There were significant relationships between total and soluble shell nitrogen which divided the Falconidae from most of the Accipitridae but left Pernis and Pandion in an intermediate position.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03015.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

The three species of widow spiders found in the Negev Desert of Israel,Latrodectus mactans tredecimguttatus, L. pallidusandL. revivensis,seem to differ more in their behaviour and habits than in their morphology. Differences in structure of the genitalia are minor compared with differences in the integument of the abdomen and the structure of the sternum.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03016.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

Anchistus custosForskål is the only common prawn commensal with bivalves of the family Pinnidae in Singapore waters. The whole morphology shows pronounced modifications connected with the commensal mode of life. The second legs are large and massive and show marked positive allometry in the male but appear to have little function in the general life of the animal. The animal occurs wherever there are established populations of matureindividuals of its host. Infestation rates are heavy and are affected by size of host and probably by competition with pinnotherid crabs. Multiple infestations are common and always involve individuals of both sexes and it has not been possible to demonstrate aggressive or territorial behaviour. Reproduction appears to occur throughout the year. Individuals are not normally found away from their hosts but rapidly abandon dead hosts. Location of the host depends in part on tactile stimuli and thigmotaxy and in part on pronounced positive rheotaxy. It has not been possible to demonstrate any distance chemical sense involved in host location but the prawn is repulsed by the presence of deadPinnaflesh. The prawn normally clings to the edge of the gill lamellae of its host and feeds by means of the highly modified first legs which are used as scrapers to remove mucus and entangled food particles from the gills of the host. Examination of gut contents of the prawn confirms this deduction. There is no evidence for any harmful effects on the host

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03017.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

A wide terminology is now in use in the study of seals. Terms which are useful for research on Grey seals (Halichoerus grypus and Common seals (Phoca vitulina)in Great Britain are redefined.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03018.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

A review is made of current information on the numbers of Grey seal(Halichoerus grypusthroughout its range. The world stock is estimated at 52,500 with 5000 in the north‐west Atlantic, 42,500 in the north‐east Atlantic (34,200 in Great Britain) and 5000 in the Bal

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03019.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03020.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03021.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1966.tb03022.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY