Applications published in the Bulletin of Zoological Nomenclature

The following Applications were published on 30 September 1999 in Vol. 56, Part 3 of the Bulletin of Zoological Nomenclature. Comment or advice on any of these applications is invited for publication in the Bulletin and should be sent to the Executive Secretary (I.C.Z.N.), c/o The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. (e-mail: iczn@nhm.ac.uk).

A recent survey of the high-mountain zone of the Madagascar Parc National (PN) d'Andringitra revealed the presence of an apparently isolated troop of the ring-tailed lemur Lemur catta. These animals display phenotypic and ecological characteristics that are unusual for the monotypic genus Lemur, thus raising the possibility that they are members of a different undescribed species. We present analyses of two mitochondrial genes to test the hypothesis that L. catta from Andringitra should be considered a distinct species. The results indicate that taxonomic revision is not warranted under the expectations of the phylogenetic, coalescent, or biological species concepts. Rather, the genetic patterns observed among the Andringitra and lowland mitochondrial haplotypes are consistent with those expected for a single species.

Brown long-eared bats Plecotus auritus occupying 30 summer roosts in north-east Scotland were studied over 15 years. During this time 1365 bats were ringed, and a further 720 recaptures were made. Individual bats showed a high degree of roost fidelity, returning to one main roost site; < 1% of recaptured bats had moved among roost sites, and all recorded movements (n = 5) were < 300 m. Adults of both sexes were loyal to the roost sites at which they were first captured, indicating long-term use of roosts. At least some juveniles (n = 32) of both sexes returned to the natal roost. Mark–recapture estimates indicated that colonies of this species were substantially larger (c. 30–50 individuals) than assumed in previous studies. Plecotus auritus differs from most other temperate zone, vespertilionid species in that there was no evidence of sexual segregation during summer, with males present in all colonies throughout the period of occupancy. Population structure in summer seems to be consistent with a metapopulation model, with discrete sub-populations showing minimal interchange. The group size, colony composition and population structure described in this species may be associated with the wing shape (particularly aspect ratio) and foraging behaviour of P. auritus. It is postulated that relative motility, linked to wing structure, may affect the distribution of individuals, and may have implications for the genetic structure of this species. Correlations between aspect ratio and both colony size and migratory behaviour, across British bat species, indicate that wing shape could be an important factor contributing to patterns of social behaviour and genetic structuring in bats.

A total of 104 Damaraland mole-rats was collected in 1988, 1990, 1991 and 1993 from an open water canal in the Otjiwarongo district of Namibia. The mole-rats were apparently dispersing above ground when they fell in and drowned; they had travelled at least 20 m in distance from their natal burrow systems. The dispersing mole-rats of both sexes were significantly larger than 73 animals trapped from a nearby control population. Sequential tooth wear and eruption patterns showed that dispersers were adult animals. There was a bias towards male mole-rats dispersing. Furthermore, in years with lower rainfall (< 300 mm) it was found that dispersal became even more male biased. Eighty per cent of males and 40% of female dispersers showed signs of reproductive readiness, with more males than females being ready to breed. Thus it appears that, in these otherwise totally subterranean mammals, at least one form of dispersal occurs, above ground, and that adult mole-rats are the principal dispersers.

Mesenchytraeus antaeus sp. n., an unpigmented giant enchytraeid inhabiting Carmanah valley (48°37′N, 124°44′W), Vancouver Island, is described. With its 102–127 segments and the size of fixed specimens reaching 61×2.9 mm (diameter maximal at midbody), this species qualifies as one of the largest members of the Clitellata family. The body wall comprises: a surprisingly thin cuticle (0.002 mm), the epidermis (0.02–0.04 mm), circular muscles (0.02 mm), plus thick longitudinal muscles (eight-layered, totally 0.16–0.18 mm) divided into seven unequal fields. The chaetae are grouped in bundles of two to seven but show some unusual traits which suggest interesting convergences with the lumbricids. For instance, the most lateral chaeta in a bundle is always the largest; the larger chaetae exceed in length one-third of a millimetre; the ectal tips of the chaetae are oriented in opposite directions in the anterior and posterior halves of the body. The spermathecal pores are prominent and open laterally in the middle of V, an unprecedented location among enchytraeids. The nature of the spermathecal ampullae (free, diverticulate and greatly elongate) indicates a close relationship to a group of species that seems to be confined to the Pacific coast of North America and the Arctic coast of Siberia. This amphi-Beringean lineage includes other gigantic forms such as M. harrimani Eisen, 1904 and M. maculatus Eisen, 1904, from which, however, M. antaeus is clearly differentiated by the lack of pigmentation, the different size distribution of the chaetae within bundles, and the unique arrangement of the male apparatus. The latter includes unusually long sperm funnels (extending over 10 segments) and two groups of large accessory glands opening through two circular papillae at the base of each penial bulb, independently of the penial pores. All other congeners known to possess this type of glands (e.g. M. franciscanus Eisen, 1904) are at most only half as large as M. antaeus. The chaetal muscles of M. antaeus are heavily infested by encysted nematodes.

We report on the geographic and temporal variation in pup condition in 20 colonies of New Zealand fur seals Arctocephalus forsteri around South Island, New Zealand during three consecutive breeding seasons, 1996–98 (n = 6856 pups) and provide hypotheses to explain the observed patterns. Three alternative data combinations are presented to calculate pup condition from body measurements and identify which combination seems to be best suited for analysing geographic patterns. A morphometric index of pup condition was best estimated by comparing all pups in all years using least-squares linear regression of the loge-transformed measurements of length vs mass. Condition varied significantly among years and colonies, but not between sexes. We also estimated seasonal changes in pup densities at colonies and investigated the relationship between pup density and condition. Mean pup densities among colonies ranged from 4.94 to 7.46 pups/100 m2 (summer) and from 4.99 to 7.04 pups/100 m2 (winter) from 1996–98, and differences between summer and winter densities varied with year. Pup density explained a significant proportion of the variation in pup condition in 1996 and 1998, suggesting that condition is partly density-dependent. After accounting for the effect of density, we found geographic differences in pup condition, and we offer alternative hypotheses to explain these differences. We also show that the 1998 El Niño coincided with a reduction in pup condition. A morphometric index of pup condition seems to be useful as an indicator of spatial and temporal variation in the marine environment.

The extent to which anti-predator mobbing can be modified in response to new predators was investigated by examining the response of terns (Sterna hirundo and S. paradisaea) and gulls (Larus fuscus, L. argentatus and L. canus) to introduced mink Mustela vison, native otter Lutra lutra and rabbit Oryctolagus cuniculus models in areas inhabited by mink and areas uninhabited by mink. Gulls and terns typically flock over predators of adult birds (a fleeing response), whilst diving at predators of chicks and eggs (an attacking response). Terns in mink-inhabited areas flocked over a model of a mink, but did not dive at it as much as they dived at otter and rabbit models. A stronger fleeing rather than attacking response suggests that adult terns perceive mink as a threat to themselves as well as to their chicks and eggs. Gulls, in comparison, dived at the mink model, indicating that mink are not perceived as a threat to the adults of these considerably larger species. Both gulls and terns showed a much lower level of response to mink in mink-free areas, suggesting that the type and extent of mobbing is altered through experience with predators and the level of risk associated with mobbing the predator.

Tadpole development was compared in three amphibian species (Bufo calamita, B. bufo and Rana temporaria) that suffer different risks of pond desiccation in nature. Using a replicated pond system, development was monitored in desiccating and non-desiccating ponds, and in vertical-sided and gently shelving (’shoreline’) ponds. In desiccating ponds, tadpoles suffered from crowding effects and metamorphosed at a smaller size, but development was not accelerated in response to desiccation in any of the three species. Desiccating ponds had higher maximum temperatures but also lower minimum temperatures, which may explain the lack of any difference in development time between desiccating and non-desiccating ponds. Although shoreline ponds were slightly warmer than vertical-sided ponds, development under these conditions was also consistent with a crowding, rather than a temperature, effect. In shoreline ponds, metamorphosis generally took longer, was less synchronized between individuals, and resulted in a smaller size at metamorphosis, compared to development in vertical-sided ponds. The lack of species-by-desiccation interactions indicated that there were no differences between the three species in developmental plasticity. Developmental constraints may place a limit on the degree of plasticity that can evolve in a species such as B. calamita, which breeds only in ephemeral ponds with a variable hydroperiod. Alternatively, low genetic variability within British populations of B. calamita may have constrained the evolution of adaptive plasticity in this species.

Recent theoretical papers on temperature-dependent sex determination in reptiles are based on the assumption that crocodilian populations, particularly adults, are markedly female biased. While there is evidence that some crocodile populations may conform to this expectation, there is no compelling evidence that American alligator populations are female biased anywhere in the species' range. Previous data had indicated that some populations of juvenile and/or adult alligators were significantly male biased. However, these studies were criticized for sampling errors. Adult males typically occupy a different habitat from that of females, and males frequent areas where they are more likely to be caught. In contrast, in juveniles, both sexes occupy the same habitat. We determined the sex ratios of c. 3000 juvenile alligators collected from 11 sites over 6 years in south Louisiana. Our results indicate a significant sex bias (58% male), but variation was evident among samples. Sex ratios varied by year and site, and the interaction of these factors was significant. At one site in one year, there was a female bias (71%), but in no year was there an overall female bias across sites. From this study and earlier reports, we conclude that there is no evidence at present of female-biased sex ratios in the juvenile and/or adult alligator populations, and consequently, that certain models of temperature-dependent sex determination in reptiles require re-evaluation. Furthermore, our data suggest a pattern of differential mortality of females vs males during the first years of life, a pattern consistent with a key prediction of several differential fitness models for the adaptive significance of temperature-dependent sex determination in reptiles.

In iteroparous organisms, maximum lifetime reproductive success is achieved through multiple successful breeding attempts. Therefore one of an individual's major life-history decisions is the allocation of resources between current and future reproduction. We studied the production of foetuses in the introduced female Canadian beaver Castor canadensis in Finland in 1992–93. The number of foetuses produced in 1993 was negatively correlated with the number produced in the previous year, irrespective of female age. Females that bred only in 1993 tended to produce more foetuses in that year than females that had reproduced in both years. However, the total number of foetuses produced was higher in females that had young in both years, stressing the importance of multiple breeding attempts in maximizing lifetime reproductive success. Despite the small size of the founder population in Finland, mean litter size and pregnancy rates were not different from North American populations.

Constriction of prey by gopher snakes Pituophis melanoleucus and king snakes Lampropeltis getula is highly variable in posture, muscular activity and force exertion. These snakes typically use lateral bends of the anterior trunk to wind the body into a vertical coil around the prey. Three common constriction postures are fully encircling loops that form a coil, partially encircling loops, and non-encircling loops that pinion the prey. Initial tightening of a coil occurs by winding or pressing the loops tighter to reduce the diameter of the coil. The epaxial muscles are highly active during striking and coil formation and intermittently active during sustained constriction. These results refute the hypothesis of a mechanical constraint on constriction in snakes with elongate epaxial muscles. Constricting gopher and king snakes can detect muscular, ventilatory and circulatory movements in rodent prey. In response to simulated heartbeats or ventilation in mice, the snakes twitch visibly, recruit epaxial muscle activity, and increase constriction pressure temporarily, but then quickly relax. Muscular activity and constriction pressure are increased most and sustained longest in response to muscular struggling in prey. Although muscle activity and pressure exertion are intermittent, the constriction posture is maintained until the prey has been completely still for several seconds; thus, a snake can reapply pressure in response to any circulatory, ventilatory or muscular movement by the prey. The pressures of 6.1–30.9 kPa (46–232 mm Hg) exerted on small mammal prey by constricting snakes range from about half to over twice a mouse's systolic blood pressure, and are probably 10 times larger than the venous pressure. These high pressures probably kill mammalian prey by inducing immediate circulatory and cardiac arrest, rather than by suffocation alone.

Though most Xenopus species are polyploid and can be hybridized in the laboratory, natural hybridization seems to be restricted to hybrids of X. laevis laevis×X. gilli. A parapatric distribution pattern between X. l. laevis and X. muelleri seems to prevent interbreeding. We found X. l. laevis and X. muelleri living sympatrically in water bodies in the Republic of South Africa west of Kruger Park and report a natural hybrid of X. l. laevis×X. muelleri. Natural occurrence of such a hybrid has not been reported previously. The hybrid character was confirmed by analysis of its advertisement calls, which were intermediate between those of the parental species, by analysis of its serum albumin pattern, and by determination of the nuclear DNA content of its erythrocytes. The results indicate that this specimen is an F1 hybrid between X. l. laevis and X. muelleri. Backcrossing with both parental species indicated that the hybrid is sterile. It is discussed why sympatry between X. l. laevis and X. muelleri though possible might be rare.

Twenty-three species of erect, fenestrate bryozoans belonging to the family Phidoloporidae Gabb & Horn 1862, popularly termed lace corals, are described from the coasts of Australia, Torres Strait and Fiji, and illustrated by scanning electron microscopy. Nine species of Triphyllozoon are re-examined, including seven originally described by Harmer (1934). Seven new species are described in Reteporella and one each in Schizoretepora and Reteporellina. Of the remaining four species, two species of Reteporellina are reported for the second time since their original description and two first described by MacGillivray (1883) are redescribed from additional materials.