摘要:

Morphometric differences and distances are theoretically equivalent whether based on Cartesian coordinate locations of landmarks, or on the linear measurements between those same landmarks. In two examples: (a) two‐dimensional primate odontometrics and (b) three‐ dimensional hominoid pelvic osteometrics, much similarity is found between analyses using input data in the form of chords and coordinates. The subtle differences attain statistical significance, however, with the greater interspecific separation and delineation of trends consistently favouring chords in one example and coordinates in the ot

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02847.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Succinic dehydrogenase activity, in the epidermis of Nairix piscutor in different stages of sloughing cycle, has been localized using a nitro‐BT technique with appropriate controls. The staining properties of different layers in scale epidermis are similar to the corresponding layers in hinge epidermis.In the stratum germinativum, the layers of undifferentiated epidermal cells in all stages of the sloughing cycle, and in the lacunar tissue of Stages 3,4 and 5, a positive though weak reaction for SDH activity reflects the active metabolic state of the cells in these layers. Loss of SDH activity in Stage 6 indicates an inactive metabolic state of the lacunar tissue cells, corresponding with their disintegration owing to the cessation of nutrients as a result of keratinization of cells in the underlying layers.The Oberhautchen, mesos and alpha layers in all Stages, and the clear layer cells in Stages 5 and 6 (outer epidermal generation), the presumptive Oberhautchen, presumptive mesos layer and presumptive alpha layer in all stages of their differentiation, and the presumptive beta layer in Stages 3 and 4 (inner epidermal generation) all stain purple with nitro‐BT technique even in sections incubated in the medium without the substrate‐succinate. The reaction is inhibited by prior treatment with 0.1 M N‐ethyl maleimide blocking protein‐bound ‐SH groups. This suggests that the reaction is due to the presence of protein‐bound ‐SH groups in these sites. The reduced intensity of reaction in the mature beta layer of the outer epidermal generation, and in the presumptive beta layer in Stages 5 and 6 of the inner epidermal generation, is due to simultaneous loss of their content of ‐SH groups with maturation a

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02848.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

General anatomy and ultrastructure of the ventral pharyngeal organs were investigated in Succocirrus krusudensis, Protodriloides chaetifer and P. symbioticus. Succocirrus papillocercus, a species without a ventral pharyngeal organ, was included for comparison. The two genera show homologous similarities in their pharynges: bulbus muscle composed of transverse muscle fibres and interstitial cells, those cells with small cell bodies and processes containing prominent tonofilaments which are orientated dorsoventrally and connect the bulbus epithelium with the investing muscle; bulbus muscle fibres circomyarian with nuclei and mitochondria located basally, investing muscle also with interstitial cells, which lack tonofilaments; oesophagus surrounded by gland cells opening into the pharynx. Most likely, a ventral pharynx with these characters was already present in the stem species of Saccocirridae, Protodriloidae fam. n. and Protodrilidae and evolutionary processes led to several changes: a tongue‐like organ with a prominent tip and supporting elements is a synapomorphic character of Protodrilus and Succocirrus; the pharyngeal organ is reduced to stomodeal pouches and salivary glands in S. papillocercus and completely lost in Asromus raenioides. These results and data from previous studies are summarized in a tentative phylogenetic dendrogram and allow the introduction of a new family, Protodriloida

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02849.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Two cave populations of Hildegarde's tomb bat had a reproductive cycle that corresponded closely to the rainfall‐induced seasonality of coastal Kenya (4s). Males had pronounced bimodal cycles of body weight due to the deposition of fat during periods of relative food abundance in both rainy seasons, and fat depletion during competitive mating and the dry seasons, when numbers of moths were lowest. The main period of sexual regeneration coincided with the increase in body weight experienced during the ‘long rains’ [April‐June) and led to mating. A secondary peak in the weights of male sexual glands, associated with the increase in body weight that occurred in the ‘short rains’ (October‐December), did not result in reproduction. It is suggested that this latter period of sexual activity was related to the maintenance of year‐round harems, and may represent the male response to a vestigial, bimodally polyoestrous, rep

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02850.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The fat sand rat (Psammomys obesus; Gerbillinae), a diurnal gerbillid rodent, is herbivorous and able to thrive while consuming only the saltbush Atriplex halimus (Chenopodiaceae), a plant relatively low in energy content and high in ash and water. We measured the basal metabolic rate offat sand rats, their energy requirements in captivity when they were offered only A. halimus, and their efficiency of utilization of this diet for maintenance.Before consuming A. halimus leaves, the fat sand rats scraped off the surface layers with their teeth. This behavioural activity removed 6.4% to 8.5% of the dry matter of the leaf, but increased the gross energy and organic matter content of the leaf by only approximately 3.1%. Basal metabolic rate of the fat sand rats was 167.9 kJ.kg‐O 7s d‐′, approximately 57% of that expected for an eutherian mammal of its body mass, and energy requirements for maintenance, or average daily metabolic rate, were 498.7 kJ.kg‐0′7s d‐′, approximately 90% of that expected for a rodent of its body mass. Dry matter digestibility of the consumed A. halimus averaged 67% and apparent digestible energy and apparent metabolizable energy averaged 65.3% and 63.4% of the gross energy, respectively. The efficiency of utilization of A . halimus for maintenance energy (k,) by the fat sand rats was 0.32 and the heat increment of feeding (HIF) was 0.68. The k, of A. halimus appeared to be low compared to other feeds, and this characteristic plus its low energy value and high water content forced the fat sand rats to consume large quantities of forage for maintenance.It was concluded that although A. halimus has a low energy and high ash content, there are several advantages for fat sand rats consuming mainly this diet. Among them are: (1) it provides a more stable diet throughout the year than do seeds; (2) fat sand rats have no competition for this food resource from other rodents; and (3) their burrows are at t

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02851.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The fat sand rat (Psammomys obesus), a diurnal gerbillid rodent, is able to thrive while consuming only the saltbush Atriplex halimus. This plant has a high ash, nitrogen and water content but low energy yield. We measured the electrolyte, nitrogen (N) and water balances of fat sand rats in captivity when they were offered only A. halimus.The fat sand rats scraped the outer layers of A. halimus leaves before consuming them. This removed 14.3% to 19.6% of the ash content of the leaves, and thus substantially reduced the electrolyte intake of the fat sand rats. Total urine osmolality ranged between 2739 and 3098 mOsm/kg, with Na+, K+ and CI ‐ comprising 74.3% to 82.5% of the total osmolytes, percentages much higher than those usually found in desert rodents. Water intake was relatively high compared to other rodents because of the high water content of A. halimus. Evaporative water loss averaged approximately 50% of the total water output. Nitrogen requirements were easily fulfilled, even when the fat sand rats did not meet their energy requirements because of the high N content of the plant. Metabolic faecal nitrogen was 70.5 mg‐kg‐′ 75.d‐′, endogenous urinary nitrogen was 171.9 mg. kg‐0′75 d‐′ and minimal N requirements were 242.3 mg.k g‐75d‐1. Minimal N requirements for the fat sand rats were approximately 98% of that expected for a eutherian mammal of its body mass.It was concluded that fat sand rats can maintain water, electrolyte and nitrogen balances when consuming only A. halimus without producing highly concentrated urine. This is due, in part, to their ability to remove much of the electrolytes before consuming the plant and by producing urine of which Na+, K+ and C1‐ comprise a large percenta

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02852.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The bilateral masseter muscle was dissected from formalin preserved heads of 41 ruminants belonging to 22 species and three feeding types. Topographic relations of the masseter portions were reexamined in relation to mandibular shape. In contrast to earlier observations, masseter weight is significantly correlated with body weight irrespective of body size and feeding type, amounting in all ruminants to approximately 0.20% of body weight. Morphophysiological differences in masseter attachment and leverage are due to the different arrangements of masseter muscle tissue.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02853.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Observations on territoriality and the associated odour‐marking and foraging behaviours in male Pachymelus limbarus Saussure, a Malagasy endemic anthophorid bee, are reported. Data indicated a monandrous mating system where virgin females are attracted, probably by pheromonal cues, to male‐patrolled territories associated with flowering, nectariferous Plectran‐ rhussensu lato species (Lamiaceae). One male observed in detail applied odour marks every 30–80 minutes on twigs around a food‐resource area that contained c. 850 flowers. This marking behaviour always preceded territory residence. The male spent c. 80% of his time patrolling. Meanwhile, any intruding flying insect was inspected or chased, which caused conspecific males, as well as often females, to leave the site. The resident male fed frequently on flowers within his territory (c. 3,600 flower‐visits on fine days), except immediately following odour‐marking bouts. His flower‐visiting was often released by interactions with intruding insects entering the territory. The observations provide the first example of male territoriality based on resource defence polygyny in the bee family Anthophoridae. The importance of resource distribution in the evolution of male territoriality in be

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02854.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

As teeth wear in eastern and western grey kangaroos, the pattern of enamel ridges changes. This affects the amount of available cutting edges and consequently the masticatory efficiency. These kangaroos also have molar progression. There is evidence for the independence of rates of tooth wear and molar progression, and variation is found in the maximum amount of wear attained by teeth both within and between populations. This variation has the potential to affect diet selection, digestion and population parameters.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02855.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Marsupials are often considered inferior to placental mammals in a number of physiological characters. Because locomotor performance is presumed to be an important component of fitness, we compared marsupials and placentals with regard to both maximal running speeds and maximal aerobic speeds (=speed at which the maximal rate of oxygen consumption, VOlmax, is attained). Maximal aerobic speed is related to an animal's maximal sustainable speed, and hence is a useful comparative index of stamina.Maximal running speeds of 11 species of Australian marsupials, eight species of Australian murid rodents, two species of American didelphid marsupials, and two species of American rodents were measured in the laboratory and compared with data compiled from the literature. Our values are greater than, or equivalent to, those reported previously. Marsupials and placentals do not differ in maximal running speeds (nor do Australian rodents differ from non‐Australian rodents). Within these groups, however, species and families may differ considerably. Some of the interspecific variation in maximal running speeds is related to differences in habitat: species inhabiting open habitats (e.g. deserts) tend to be faster than are species from habitats with more cover, or arboreal species.Maximal aerobic speeds (compiled from the literature) were higher in large species than in small species. However, marsupials and placentals show no general difference with regard to maximal aerobic speeds.Maximal running speeds and maximal aerobic speeds for 18 species of mammals were not correlated, after correcting for correlations with body size. Thus, the fastest sprinters do not necessarily have high maximal aerobic speed

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1988.tb02856.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY