A new species of leptodactylid frog is described from Parque das Mangabeiras, in Belo Horizonte, Minas Gerais, south-eastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and is characterized by medium size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger and toe discs with well-developed scutes, a weakly developed stripe on the upper lip, dorsum, arm, leg, and foot dark brown with small irregular brown and black dots, and absence of red and yellow spots in live specimens. The descriptions of the tadpoles and vocalizations, and information on natural history are provided. Hylodes perplicatus (Miranda-Ribeiro), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

The shell and anatomy of Nipponomysella subtruncata is described. The bivalve is attached singly or in groups of up to nine on Siphonosoma cumanense, a burrowing intertidal sipunculan in south-west Japan. The species is a protandrous hermaphrodite. Specimens 1.4–2.5 mm long are males, which between 2.1 and 3 mm in length reverse sex and remain females. Reproduction peaks in summer and the annual number of clutches is small. Ripe oocytes, 84–88 μm diameter, are spawned into the suprabranchial cavity where they develop into 107-μm-long straight-hinged veligers. Following a planktotrophic period of unknown duration, the c. 360-μm-long spat normally settle upon and attach to the shells of larger, predominantly female, individuals. At a length of 1–1.6 mm they detach again and live separately thereafter. Sperm are transferred in spermatophores and stored within paired, mushroom-shaped receptacles located posteriorly in the female's suprabranchial cavity. The receptacles first appear in large males or in specimens in the process of reversing sex. Stored sperm probably survive long enough to fertilize more than one clutch. The anatomy of Nipponomysella is characteristic of the Montacutidae, and is of especial interest because of the unique structure of the sperm receptacles.

In this study we tested the nature of the phoretic relationship between the cosmopolitan mite Macrocheles merdarius and the dimorphic dung beetle Onthophagus binodis. We observed and experimentally manipulated the number of mites on individual beetles and tested how mite infestation affects male longevity. There was a significant effect of mites on male longevity: males in our mites-added treatment died on average 15 days earlier than males in our mites-removed treatment. Interestingly, the number of mites on males was significantly repeatable suggesting that individuals may differ in their susceptibility to infestation. Major males had more mites on them than minor males, and the proportion of mites on minor males was negatively density dependent.

A total eclipse of the sun is a very rare event for a given geographical location, and it is not easy to predict the reaction of animals to such events. On 11 August 1999, the reaction of some species of Saltatoria was quantitatively analysed in a long-term study area for which the normal diurnal song patterns are well established. The song activity of the grasshoppers and bushcrickets declined slowly during the partial eclipse, and stopped completely during the 2-min total eclipse. After a marked delay, song activity returned suddenly to normal. This suggests that light intensity is the main parameter controlling the diurnal song pattern in the species studied, and obviously overrides any internal rhythm.

Tidarren argo sp. nov. is described from Yemen. As in its congeners, the male amputates one of his palps before maturation and enters his adult life with one palp only. The new species is shown to adopt exceptional copulatory behaviour. As soon as the male achieves genitalia coupling with his palp, the palp is torn off by the female. The separated gonopod remains attached to the female's epigynum for c. 4 h and apparently continues to function independently. Furthermore, it serves as a mating plug. In the meantime the female feeds on the palpless male. Emasculation synchronizes sexual cannibalism and sperm transfer, and may lengthen the interval between copulations. This unique mating behaviour probably allows continuation of insemination by the dismembered palp and is reported for the first time.

The mormyrids are well known for their remarkable electrogenic and electrolocation capabilities and exceptionally large cerebellum that may account for much of their total oxygen consumption. Mormyrids living in oxygen-deficient waters may use oxygen efficiently, protecting the brain from hypoxia damage; and/or brain size may be reduced. This study compares the TFL, gill lamellar density, gill lamellar area, total gill surface area, and brain size of two species of mormyrids from extremely hypoxic waters in Uganda (Gnathonemus victoriae and Petrocephalus catostoma) to two open-water species (Mormyrus kannume and Gnathonemus longibarbis) from the same region. In addition, interdemic variation was considered by comparing swamp populations of G. victoriae and P. catostoma to open-water populations of the same species. Total gill surface area of all species fell within the upper range for freshwater fishes. However, there were both intraspecific and interspecific differences in gill characters. Interdemic comparisons showed larger gill size in swamp-dwelling populations. Brain size varied among species; larger brains were characteristic of species from well-oxygenated waters. Large gill surface area may permit survival of mormyrids in oxygen-stressed environments; however, mechanisms compensating for hypoxia seem to be inadequate to support a brain size as large as that seen in fish from well-oxygenated waters.

An existing spatial population model, developed to assess the reintroduction of the European beaver Castor fiber to Scotland, was applied to predict the likely result of reintroducing beavers to Norfolk, England. A habitat analysis was conducted using the Land Cover Map (classified satellite imagery developed by the Institute of Terrestrial Ecology) to predict the location of areas suitable for beavers. The model was used to simulate population processes within these areas and dispersal between them following a range of reintroduction scenarios. To represent uncertainty regarding the probable behaviour of beavers in Norfolk, the habitat analysis and model were applied using three sets of parameter values (high, medium and low) derived from the literature. It was predicted that Norfolk could support between 18 and 40 beaver families. Using high or medium parameter values, beaver populations were predicted to expand following reintroduction and spread to new areas. Using low parameter values populations were predicted to decrease, risk extinction and not colonize new areas. This analysis is a preliminary investigation into the likely fate of beavers in Norfolk. Checking the estimates of habitat availability in the field would enable greater confidence to be placed in these predictions.

The paper reports on a new family of spiders from the eastern Cape region in South Africa. Chummidae, new family, are small, three-clawed spiders, recognized by the abdomen with strong dorsal scutum, provided with a frontal field of stiff macrosetae in large sockets. Further apomorphies are the absence of a fovea, the reduction of posterior and median spinnerets, the absence of major ampullate gland spigots, and the presence of branched lateral tracheae and of a hair-basket around the cheliceral fang. The type genus Chumma, is represented by two species, both known from male and female – the type species C. inquieta sp. nov. and C. gastroperforata sp. nov. The males of the latter species are remarkable for having two pairs of abdominal pockets, which play a role during mating.

The reproductive pattern of the female Angolan free-tailed bat Mops condylurus (A. Smith, 1933) was investigated at two localities in Mpumalanga. Female Angolan free-tailed bats displayed a seasonal bimodally polyoestrous reproductive pattern. Parturition in December was followed closely by a post-partum oestrus. Ovarian follicle and endometrium cycles also closely followed the breeding season. The reproductive tract displayed complete dextral dominance with the right ovary and uterus being functionally dominant. Luteal activity was maintained throughout pregnancy and healthy corpora lutea were observed until late in pregnancy. Shedding of the zona pellucida occurred in the oviduct in the region of the ampulla–isthmus junction. The embryo entered the uterus as a morula, where it was transformed into a unilaminar, free-lying blastocyst. A unique feature of the pre-implantation uterus was the formation of a distinct decidua at the implantation site on the mesometrial side. Implantation in the Angolan free-tailed bat was centric and superficial. First attachment of the trophoblast to the endometrium was mesometrial. The formation of a pre-placental pad of trophoblast cells was also initiated on the mesometrial side, while orientation of the embryonic disc was anti-mesometrial. Placental development occurred in the abembryonic hemisphere. Proliferation of the trophoblast over the embryonic hemisphere was slow and a bilaminar arrangement of the trophoblast was not observed in this region until after the primitive streak stage.

The relationship between wing morphology and ability to manoeuvre through an obstacle course was examined in five species of bats in the Neotropical family Phyllostomidae. These species represent a range of morphologies and feeding adaptations: Tonatia silvicola, a surface-gleaning insectivore; Artibeus jamaicensis and A. literatus, canopy frugivores; and Carollia perspicillata and C. castanea, understory frugivores. Bats of known morphology were presented with three different obstacle arrangements chosen in random order. In order to control for wing span, spacing between obstacles was scaled to the wing span of the individual (1×, 0.75×, 0.5× the wing span of the bat). Performance was measured as the number of times a bat hit an obstacle hard enough to deflect it. Morphological variables were analysed using principal components analysis and were summarized by the first two principal components (PC): PC 1, ‘size’, with which size-related variables were strongly, positively correlated; PC 2, ‘camber’, on which variables associated with maximum depth of wing camber weighted most heavily. Obstacle course performance was significantly correlated with both size and camber at all obstacle spacings: larger bats hit more obstacles, even though obstacle spacing was scaled to wing span, and bats with better ability to camber wings hit fewer obstacles. These results show that bat species that forage in more cluttered habitats are more likely to be small in size and/or have wings able to produce the high camber necessary to maintain lift at low flight speeds.

Reproduction and postnatal development of the southern African bush Karoo rat Otomys unisulcatus was studied in the laboratory. Fifty-one litters were obtained from 17 pairs, with a mean litter size of 2.09, reproductive effort of 0.58 and gestation period of 37 days. Neonates weighed 6.1–9.6 g and were semi-precocial. Weaning began as early as 8 days of age, and the age at first reproduction was 6 weeks in males and 5 weeks in females. Compared to its congeners, O. unisulcatus has small litters of semi-precocial young which undergo rapid postnatal development, and contrary to expectations displays several K-selected reproductive characteristics. The reproductive biology and postnatal development of the bush Karoo appears to reflect a compromise between exploiting sporadically abundant resources and the occupation of stick lodges, which may provide a favourable microclimate to buffer the harsh external climate.

The pecten oculi is a highly vascularized and pigmented organ that overlies the optic disc and projects into the vitreous body in the avian eye. First reported over 300 years ago, its function(s) remains a puzzle to ornithologists, ophthalmologists and anatomists. Morphometric study of this unique organ was undertaken in birds exhibiting apparently different visual acuities, namely two species of diurnal birds (the ground-dwelling domestic fowl Gallus gallus var. domesticus and a highly active predator bird, the black kite (Milvus migrans) and a nocturnal bird (the spotted-eagle owl Bubo bubo africanus). The volume of the owl's eye was 4.8 and 2.2 times larger than that of the fowl and the kite, respectively. However, the pecten of the fowl consisted of more pleats (16–18) compared to the kite (12–13) and the owl (5–6). The volume of the pecten of the kite was 1.4 and 2.7 times larger than that of the fowl and the owl, respectively (P < 0.05). Similarly, the surface area of the pecten of the kite was 2.6 and 4 times larger than that of the fowl and owl, respectively (P < 0.05). The volume density of blood vessels (lumen and wall) in the pecten of the kite, fowl and owl comprised 67.7%, 66.9% and 62.6%, respectively, the pigmented tissue constituting the rest. Both the volume density and the volume of the blood in the pecten were higher in the diurnal birds (kite, fowl) than the owl (P < 0.05). The surface area of the capillary luminal surface was 1.7 and 5.3 times higher in the kite than in the fowl and the owl, respectively (P < 0.05). These results suggest that the functional morphology of the pecten correlates with the life-style of the bird and with functional need, and lends further support to the nutritive role of the pecten.

The Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis-Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Semi-arboreal habits appeared only in forest forms. Semi-arboreals are significantly more slender and have longer tails than terrestrials; body size is not significantly different between terrestrials and semi-arboreals. Within Bothrops, independent contrasts for macrohabitat use were significantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi-arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversification of Bothrops in South America.

The compactness of bone tissue was measured in the shaft of the femur, tibia and fibula in 390 male and female Nile monitors Varanus niloticus from three distinct regions of Sahelian Africa. In males, bone compactness increases during ontogeny in the three bones. Conversely, in females, it tends to decrease in the femur and, to a lesser extent, the tibia, but not in the fibula. In addition to this long-term trend, gravid females have lower femoral compactness than mature non-gravid ones. Moreover, important differences are noticeable between local samples, indicating that the variation in bone compactness during ontogeny is a flexible or even a facultative process. Histological observations reveal the existence of an extensive remodelling by resorption and reconstruction on the walls of the marrow cavity in the femur and tibia, and the complete absence of Haversian substitution. It is concluded from these data that: (1) during ovogenesis, female Nile monitors recycle skeletal calcium through cortical resorption in certain bones, if the calcium supply from food is not enough; (2) this remodelling process is not balanced, which creates a long-term tendency towards a deficit in reconstructive bone, and a consecutive decrease in the compactness of the skeletal elements involved. The comparative and functional aspects of these results are discussed.

A feral population of African clawed frogs Xenopus laevis from a small pond in South Wales was sampled continuously for 2 years to assess morphometric growth. Toe-clips taken at intervals over a 4-year period were found to contain lines of arrested growth (LAG) which corresponded to each consecutive winter. The first toe-clips revealed a population structure within the pond consisting of a dominant cohort of frogs with one LAG that metamorphosed in 1993, and a few older individuals. Subsequent toe-clips in 1996 and 1998 gave two and four more LAG, respectively. Morphometric growth was found to be restricted to a short growing season, significant differences in the growth rates of males and females being first detected in their third growth season. Reproductively active frogs were still within their initial period of growth, suggesting that Xenopus laevis does not conform to the standard energy resource allocation mechanisms of typical ectotherms.