摘要:

The major chelipeds of five species of decapod crustaceans were studied with reference to lever system mechanical advantage, pattern of occlusive geometry, and force/pressure developed during cheliped closure by intact animals. Every cheliped type was found to possess a linear array of two to four distinctive regions of occlusion. The factors responsible for the differences in occlusive design are discussed. It is suggested that crustacean major chelipeds must be regarded as regionally‐specialized, multifunctional appendage

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03397.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The fore‐ and hindlimb muscles of 12Setonix brachyurusjoeys, aged 5 to 175 days postpartum, and four adults were dissected out and weighed. Individual muscles and muscle groups were analysed for absolute and relative growth changes. From comprising almost 59% of the total limb musculature at birth the forelimb muscles finally constitute just over 9% in the adult; the hindlimb muscles start at just over 41% and end at almost 91%. In both limbs, the extensor actions predominate in the proximal limb segment because of their propulsive functions, whereas in the distal segment the flexor muscles tend to be the larger because of their shock‐absorbing and spring functions. During growth of the fore‐limb there is a relative increase in the size of latissimus dorsi and triceps brachii and a decrease in the distal segment muscles; in the hindlimb the gluteal and hamstring muscles increase at the expense of the distal segment muscles. Specializations for speed include long distal hindlimb segments and proximally located muscle bellies. The above findings reflect the adaptations and changing locomotor patterns from birth to adult in the Q

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03398.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Pitfall traps were set and visual observations made along regularly walked transects to assess the patterns of surface activity ofOmmatoiulus moreletiiin open grassland and dry sclerophyllous woodland in South Australia. ActiveO. moreletiiwere most commonly seen and trapped in autumn, to a lesser extent in spring, occasionally in summer and rarely in winter. Day to day variations in activity were related to changes in temperature and moisture. The activity of older stadia was greater than that of younger stadia.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03399.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Territorial behaviour and thermal ecology in relation to heat resistance in the tree agama (or black‐necked agama),Agama atricollis, were studied during two expeditions 1951–2 and 1958–9 in eastern Zaire (the former Belgian Congo) in an area just south of the equator. The maximum temperature tolerance ofA. atricollislies within the range of 43–43·9°C, but the maximum voluntary tolerance is somewhat lower, 42·5°C. Territorial males, retreating from their guard posts after having exposed themselves to direct sunlight during the hottest hours of the day for 10–16 minutes, reach body temperatures of 42·2–42·5°C before they retreat into the shade. In shady places it takes the males from 14 to 21 minutes to cool down to 38·1–39·9°C, at which body temperatures they return to the lookout within the territory. The territoriality inA. atricollisand several other species of the same genus, as well as other diurnal lizards with similar behaviour, may have contributed, through selection, to the evolution of their extraordinary resistance to substratum heat and direct sunlight. In an attempt to review and compare maximum voluntary body temperatures (MVT), critical thermal maxima (CTM) and lethal body temperatures (LT) in reptiles with pronounced heat resistance, data have been compiled for 96 species representing 11 families and six continents. The family Agamidae appears to be the most adapted to high body temperatures with 13 species (of 18 species tested) having body temperatures above 43°C in comparison with six species in Iguanidae (of 33 species tested), four in Gekkonidae (of nine species tested) and so forth. Agamids, iguanids, teeids and geckos, in hot environments of five continents, have evolved along the same lines behaviourally and physiologically as responses to territoriality in combination with high temperatures. This feature may be of adaptive significance.This paper also reports on body temperatures, obtained in Africa from free‐living individuals of seven other species of the generaAgamaandMabuya, namelyA. atra, A. colonorum, A. hispida, A. planiceps, Mabuya quinquetaeniata, M.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03400.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The vascular anatomy of the head and neck of eight adult helmeted guineafowl (Numida meleagris) was investigated by latex injections and dissection, resin casting, and lipidol injections and X‐ray photography. The vascular anatomy of these regions is similar to that of the domestic fowlGallus domesticus, the main differences being in the helmet, wattle and cere vascularization, and the presence of a nape‐cheek rete inN. meleagris. It is postulated that five vascular arrangements in the head and neck are important in brain temperature regulation. These arrangements are: the nape‐cheek rete, the temporal rete, fine arteriovenous networks in the wattles and cere, and the cavernous sinus‐intercarotid association. All but the last of these arrangements require pathways of blood flow to the brain other than the most direct route. Such pathways are di

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03401.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Several aspects were studied of the reproductive biology of the Red panda,Ailurus fulgens, in captivity at the National Zoological Park (NZP), Washington, D.C. over a six‐year period. This species exhibits marked mating and birth seasons and produces litters averaging 1·7 with a sex ratio of 17·2 males to one female. Sexual maturity is reached in the second breeding season after birth or when animals are approximately 18 months of age. Growth, development and mortality of young are discussed. This study noted a wide range in observed gestation periods, averaging 131 days, which may be due to one or a combination of factors. Breeding behaviour is briefly noted and compared to that in other, related species. Predictions about reproductive and other life strategies of Red pandas in nature are drawn by fitting captive data into accepted ecological mod

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03402.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The development of social behaviour was studied in three natural populations of Bighorn sheep (Ovis canadensis). Individuals in all populations exhibited the same behavioural repertoires, but the utilization of specific behaviours among both infants and adults differed between populations. It was suggested that differences in the adult utilization of behaviour patterns result in part from behaviours used during infancy. In turn, the social and physical environments affected the development of subsequent behaviour patterns in sheep older than lambs.Desert sheep (in southern California) used mounting behaviours often, presumably because they matured sexually at an early age. Sheep in a more northern environment (British Columbia) used different behaviour patterns more frequently perhaps as a consequence of interactions experienced in larger bands. Additionally, playful interactions were reduced due to physical hazards in the desert, but they were at least nine times as frequent in the northern study population. Play in large groups resulted in the utilization of more different kinds of behaviour patterns. These behavioural findings are interpreted ecologically as consequences of inhabiting environments that differ socially and physically.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03403.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The frond‐like fimbriae surrounding the oral disc of the lamprey,Geotria australis, have been examined in living specimens, and by using histological, histochemical and ultra‐structural techniques. Approximately 57 fimbriae are present in this species, with those at the posterior end of the disc being significantly larger than those in the anterior and lateral regions. The terminal finger‐like projections of the fimbriae possess a stratified epithelium composed solely of a series of rows of mucous‐producing cells. Tests have shown that the mucus of the epithelial cells contains large amounts of N‐acetyl neuraminic acid. Since the adjacent fimbriae are closely apposed when the lamprey is using its oral disc for suction, it is suggested that their flexible shape, mucous secretions and production of an increased surface area for attachment, help to provide a more efficient seal. Since fimbriae are present in all lampreys except those species belonging to the Mordaciidae, it is postulated that their absence in this latter family can be related to known differences in the behaviour of their adu

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03404.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03405.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1979.tb03406.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY