Evidence of multiple divergent mitochondrial lineages within the southern African diplopod genus Bicoxidens Attems, 1928 (Spirostreptida)

Two recent studies have suggested that divergent mitochondrial lineages may be present within spirostreptid genera such as Bicoxidens Attems, 1928. Bicoxidens, similar to many other endemic soil invertebrates, exhibits low dispersal capabilities and strict microclimate habitat preferences, attributes that often lead to geographic isolation. Given that prolonged geographic isolation often lays the foundation for population genetic differentiation, genetic divergence and possibly speciation, there was good reason to suspect that Bicoxidens may consist of several distinct lineages. On this basis, the mitochondrial cytochrome c oxidase subunit 1 (COI) was used to reconstruct the phylogeny of Bicoxidens and reveal divergent lineages within the genus. Maximum likelihood and Bayesian inference analyses recovered a paraphyletic Bicoxidens phylogram with divergent lineages present in three species – B. friendi, B. flavicollis and B. brincki – suggesting high genetic diversity within the genus. Bayesian genetic cluster analyses suggested the presence of multiple distinct mitochondrial lineages within the genus with four identified in B. flavicollis alone. It was therefore concluded that the divergent lineages observed among Bicoxidens populations may suggest the presence of hidden species.     

Goblet Cell Types in Intestine of Tiger Barb and Black Tetra (Cyprinidae,Characidae: Teleostei)

Histochemical properties of goblet cells in intestine of a stomach‐less teleost, tiger barb (Puntius tetrazona), and a stomach‐containing teleost, black tetra (Gymnocorymbus ternetzi), are described and compared. The intestine goblet cells were mostly wide in both species, but in tiger barb, some of them were markedly thinner. In black tetra, all the intestine goblet cells displayed magenta colour after PAS, whereas in the tiger barb, only the thinner goblet cells displayed such affinity. The latter cell type was coloured strongly magenta when the tissue was treated with alcian blue (pH 2.5) followed by PAS, whereas the wide goblet cells in tiger barb and all goblet cells in black tetra displayed mainly a blue colour after such treatment. Further, the goblet cells in both species were coloured cleanly blue after high iron diamine followed by alcian blue (pH 2.5). The intestine goblet cells in both species displayed a moderate affinity to WGA and concanavalin A lectins and no affinity to DBA. Most of the goblet cells displayed no affinity to PNA, but some of them in the tiger barb displayed a moderate or strong affinity to this lectin. The affinity to WGA was somewhat strengthened after pre‐treatment with neuraminidase. These results suggest that tiger barb contains two types or variants of intestinal goblet cells: high numbers of wide cells filled by acidic, non‐sulphated mucin and some thinner cells filled by neutral mucin. The intestine goblet cells in black tetra were filled by variable amounts of neutral and acidic mucin, but the total number of such cells is much less than in tiger barb. The present lectin and neuraminidase results suggest that the intestinal mucins in both species contain significant amounts of N‐acetylglucosamine, sialic acid and glucose/mannose, but seem to lack N‐acetylgalactosamine. However, some of these cells in tiger barb contain moderate to large amounts of galactose. Together, these results suggest significant species‐specific features of the intestine goblet cells and mucin types in tiger barb and black tetra. In conclusion, the present results suggest that the diet and feeding habits in stomach‐less teleosts compared with stomach‐containing teleosts, greatly influence the number of intestine goblet cells and type of mucin in these cells.     

A New Freshwater Goby (Teleostei: Gobiidae) from the Pongolo Floodplain,Zululand, South Africa

A new freshwater goby, Mugilogobius pongolensis sp. n. is described and figured as a species new to southern and eastern Africa. This record extends the zoogeographcal distribution of Mugilogobius Smitt, 1899, from the Indonesian archipelago and South Australia to the Indian Ocean and the eastern coast of Africa.     

Cytosystematics of the South African Aethomys (Rodentia: Muridae)

The G-and C-band chromosome patterns and the location of the nucleolus organizer regions (NORs) are presented for A. namaquensis (2n = 24), A. granti (2n = 32) and A. chrysophilus (2n = 44; 2n = 50). The presence of two distinct cytotypes in what is conventionally recognized as A. chrysophilus is indicative of the presence of two discrete species which, karyology apart, appear to be indistinguishable using existing identification keys. The chromosomal relationships of the South African species and the taxonomic implications of these data are discussed.     

The effect of temperature on the rate of passage of food in the smallmouth yellowfish,Barbus aeneus Burchell (Teleostei,Cyprinidae)

The effect of temperature on the rate of gut evacuation in Barbus aeneus was investigated in two ways. In the first, juvenile fish, kept under conditions of constant temperature, were fed marked food items and the time elapsing until these appeared in the faeces was noted. In the second, fish of a range of sizes were caught in the P.K. le Roux dam and immediately placed in cages in the dam to prevent their access to food. Groups of fish were sacrificed at intervals and the contents of standardized gut sections weighed. The field experiment was carried out in summer and in winter. The laboratory experiment yielded the relationship: P = 6270 × t^-2,11 where P is the passage time in hours and T is the temperature in °C. This gives passage times of the order of 8 h at 25°C and 39 h at 11,5°C. The field experiment indicated that there was an exponential relationship between degree of fullness and rate of evacuation, and that complete evacuation required about 24 h in summer, but more than 5 days in winter.     

Preliminary Observations on the Relationships of Barbus Species From Cape Coastal Rivers,South Africa (Cypriniformes: Cyprinidae)

Observations on the phylogenetic relationships of Barbus species from the southern Cape Province are made in the light of new data on the post-cranial axial skeleton and other osteological and anatomical features. Particular attention is paid to the relationships of the ‘red fin’ Barbus species, and new evidence on the problematical relationships of the rare African cyprinid species Oreodaimon quathlambae, is presented.     

New evidence of homoplasy within the African genus Varicorhinus (Cyprinidae): an independent origin of specialized scraping forms in the adjacent drainage systems of Ethiopia inferred from mtDNA analysis

Interrelationships of the two specialized scraping periphyton-feeders, Varicorhinus beso and V. jubae, and some large African barbs, Labeobarbus spp., inhabiting three main regions of Ethiopia (the Western and Eastern Plateaus, and the Rift Valley separating them) were investigated using the sequence analysis of a fragment (609 base pairs) of the mtDNA control region. The two scraping forms in question appeared to be phylogenetically distant: V. beso had branched off before the main radiation of the Ethiopian Labeobarbus took place, whereas V. jubae is a sister group of the Labeobarbus gananensis complex sympatrically occurring with it in the south of the Eastern Plateau. For geographical reasons, among the congeneric species, V. jubae could be considered as the most closely related to V. beso, the type species of the genus, but judging from the available data this genus seems to be monotypic, while jubae should be classified as a member of Labeobarbus.     

Studies on the Taxonomy of the South African Tectocepheidae Grandjean 1953 (Oribatei,Acari)

Mousebirds (Coliiformes) exhibit well-developed communal roosting behaviour as well as a pronounced capacity for facultative hypothermic responses. We recorded body temperature (T_b)) in speckled mousebirds (Colius striatus) under semi-natural conditions in outdoor aviaries, and examined interactions between behavioural and metabolic thermoregulation by experimentally manipulating food availability and communal roosting behaviour. When food was available ad libitum, mousebirds roosting in a cluster maintained approximately constant rest-phase T_b, with 32°C < T_b < 42°C. By contrast, rest-phase T_b in single mousebirds decreased at 0.5°C/hr and minimum rest-phase T_b was significantly lower than when clustering. When food availability was restricted, the mousebirds exhibited facultative hypothermic responses that were less pronounced in clustering groups (minimum rest-phase T_b = 33.3°C, circadian amplitude of T_b = 9.5°C) compared to single birds (minimum rest-phase T_b = 30.7°C, circadian amplitude of T_b = 11.8°C). When clustering, rest-phase T_b was highly synchronized among individuals. Our data reveal that communal roosting has profound consequences for rest-phase thermoregulation in C. striatus, and provide further insights into the potential role of physiological constraints in the evolution of avian sociality.     

Age,Growth and Aspects of Reproduction of the Mackerel Scomber Japonicus in South African Waters (Pisces: Scombridae)

The age and growth of the mackerel were determined from 1742 otoliths collected from commercial catches. The time of annulus formation was established from otolith edge examinations. Two zones. one opaque and one hyaline, are laid down during a year. The distance of each annulus from the nucleus of the otolith was measured. Mean measurements were substituted in a linear regression equation which describes the relationship between otolith radius and fish length to obtain back-calculated length at age values. Growth in length and in mass are expressed by the von Bertalanffy growth equation. Length and age at first maturity were established by macroscopic examination of mackerel gonads. All mackerel were found to mature during their fourth year of life, at 42 cm standard body length. Spawning takes place during the period June to September.     

Incisor morphology as an aid in the systematics of the South African Leporidae (Mammalia: Lagomorpha)

Photomicrographs of cross-sections through the principal upper incisors of the South African Leporidae were evaluated for use in species identification. Differences in incisor width and the pattern of the enamel fold provide a reliable means of distinction between Lepus capensis and L. saxatilis. Incidental comparisons of incisor cross-sections of the South African L. capensis, including those from the type locality, and the taxonomically controversial L. europaeus reveal marked differences which may be useful in the delimitation of these taxa. Within Pronolagus, distinct differences were evident between the incisor patterns of P. rupestris and its congeners, P. crassicaudatus and P. randensis, which are similar with respect to this character. Similarly, striking differences were evident between the incisors of the monotypic Bunolagus monticularis and both L. saxatilis and, importantly in view of their close phenetic relationship, L. capensis.     

Glycoproteins in the Buccal Epithelium of a Carp,Cirrhinus mrigala (Pisces,Cyprinidae): A Histochemical Profile

Glycoproteins (GPs) were visualized histochemically in the secretory cells – the mucous goblet cells (the type A and the type B), the rodlet cells and the epithelial cells in different regions of the buccal cavity of Cirrhinus mrigala. The type A mucous goblet cells, the type B mucous goblet cells, the rodlet cells and the epithelial cells elaborate GPs with oxidizable vicinal diols and GPs with sialic acid residue without O‐acyl substitution. The type A mucous goblet cells, in addition, contain moderate amounts of GPs with O‐sulphate esters. The type B mucous goblet cells, in contrast, contain high concentrations of GPs with O‐sulphate esters. The rodlet cells secrete small amounts of GPs with oxidizable vicinal diols. The analysis of the results elucidates interesting differences in the composition and concentration of GPs in the mucus elaborated by the secretory cells indicating the potential importance of the glycoproteins in the buccal cavity. These GPs could be considered to represent a mechanism for modulation of the composition of the protective mucus layer correlated to specific functions.     

First account of the metazoan parasite fauna of oilfish Ruvettus pretiosus Cocco, 1829 (Perciformes: Gempylidae) in South African waters

Parasites are an important but neglected component of ecosystems that can be used as indicators of host biology and ecology. In the present study, the metazoan parasite assemblage of Ruvettus pretiosus, an understudied but widely distributed predatory gempylid, caught off South Africa was surveyed. A total of seven parasite taxa, including four new infection records (Bolbosoma capitatum, Rhadinorhynchus sp., Hepatoxylon trichiuri and Anisakis sp.), two new locality records (B. capitatum and Rhipidocotyle sp.) as well as the ectoparasitic copepod Sagum foliaceus and the cestode Tentacularia coryphaenae were recovered from the eight specimens examined.     

Parasites of South African wildlife. XVIII. Cooperia pigachei n. sp. (Nematoda: Cooperiidae) from the mountain reedbuck, Redunca fulvorufula (Afzelius, 1815)

A new species of Cooperia, for which the name Cooperia pigachei n. sp. is proposed, was recovered from a mountain reedbuck, Redunca fulvorufula, from the Sterkfontein Dam Nature Reserve, Free State Province, and is described and illustrated. It is close to Cooperia neitzi M?nnig, 1932 and the South African race of Cooperia rotundispiculum in having more than 14 longitudinal cuticular ridges and in that the lateral cervical synlophe is of the closed type. The new species differs from all the other species of the genus in that the lateral branches of the dorsal ray are large and T-shaped. The spicules are robust, over 0.3 mm long and have large, curved shoes on their tips.     

The epidemiology of tuberculosis in free-ranging African buffalo (Syncerus caffer) in the Kruger National Park, South Africa

The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is currently spreading in a northward direction. It was estimated that this northward spread took place at a rate of about 6 km per year; the prospect being that, if this rate of spread is maintained, the entire KNP may be affected in less than 30 years from now. Spillover from buffalo had already occurred in species such as chacma baboon (Papio ursinus), lion (Panthera leo), cheetah (Acinonyx jubatus), kudu (Tragelaphus strepsiceros) and leopard (Panthera pardus). Although there is no indication yet that these species act as maintenance hosts, the possibility is raised that these, or an as yet overlooked species, might assume such a role in future. In the KNP, BTB manifests itself as a chronic and predominantly subclinical disease in buffalo. It may take years for clinical signs to develop, and then only at a terminal stage, when emaciation is a constant feature. It is suspected that the time from infection to death is variable and dependent on the animal's immune response, which can be weakened by such factors as stress, old age or droughts. It was found that, in the interim, buffalo have a normal reproductive life. On necropsy, buffalo show almost exclusively lung and upper respiratory tract involvement, pointing to an aerogenous mode of transmission. Histologically, little sign of encapsulation of lesions was detected, which suggests that they are exceptionally susceptible to BTB and that most lesions are open and infectious and progressive, leading ultimately to death of the individual. Evidence also indicates that BTB is progressive within the herd context (92% being the highest prevalence rate thus far determined in a buffalo herd) as well as progressive within the KNP buffalo population (the implication being that virtually all buffalo herds in the KNP will eventually be infected). Preliminary data suggest a positive correlation between disease prevalence and mortality, with potential mortality reaching up to 10% in buffalo herds having BTB prevalence rates of 50 % and higher. Only the future will tell what the effect of the disease on the population dynamics of buffalo will be.     

Parasites of South African wildlife. XVII. Ostertagia triquetra n. sp. (Nematoda: Trichostrongylina) from the grey rhebuck,Pelea capreolus (Forster, 1790)

Re-examination of Teladorsagia hamata (M?nnig, 1932) Durette-Desset, 1989 reported from grey rhebuck, Pelea capreolus (Forster, 1790) proved it to be a new species of Ostertagi Ransom, 1907. The new species, for which the name Ostertagia triquetra n. sp. is proposed, differs from Teladorsagia hamata in the configuration of the bursal rays (2-1-2 in the former, 2-2-1 in the latter), and in that the interno-dorsal branch of the spicules bears a process that is triangular and convex in the new species, but concave and shaped like an ice-cream scoop in Teladorsagia hamata. Ostertagia triquetra has so far been found only in grey rhebuck in the Eastern Cape Province while Teladorsagia hamata was recorded from springbok, Antidorcas marsupialis (Zimmerman, 1780) and gemsbok, Oryx gazella (Unnaeus, 1758) in the western part of the country.     

Studies on the parasites of zebras. IV. Cylicodontophorus reineckei n.sp. (Nematoda: Strongylidae) from the Burchell's zebra, Equus burchelli antiquorum H. Smith, 1841 and the mountain zebra, Equus zebra hartmannae Matschie, 1898

A new species of nematode, Cylicodontophorus reineckei, was collected from Burchell's zebra, Equus burchelli antiquorum H. Smith, 1841, in both the Etosha National and Kruger National Parks and from mountain zebra, Equus zebra hartmannae Matschie, 1898, in the Namib Naukluft Park in South West Africa/Namibia. These nematodes have an external leaf-crown with longer elements than those of the internal leaf-crown and a well-developed dorsal gutter. The very well-developed oesophageal funnel is both wider and deeper than the buccal capsule.     

Neocucumis kilburni sp. nov. (Echinodermata : Holothuroidea : Cucumariidae) from the east coast of South Africa,with a key to the genus Neocucumis

A new dendrochirotid holothuroid, Neocucumis kilbumi, is described from waters 50 meters deep, off the southern coast of KwaZulu-Natal, South Africa. It appears quite close to N. watasei (Ohshima) and N. sordidatus (Sluiter), both from the West Pacific and to N. atlanticus (Ludwig & Heding) from the Atlantic Ocean and the Mediterranean Sea. It differs from the former in the nature of the calcareous ring and the disc and the spire of the body wall tables, from N. sordidatus in the completeness of its deposits and the number of polian vesicles and from N. atlanticus in the presence of handles to the quadrilocular table discs. The new species increases to ten the number of species now classified in the genus Neocucumis. A key to all the species is included.     

Redescription of some Thelandros and Tachygonetria spp. (Pharyngodonidae: Oxyuroidea) from the omnivorous plated lizard,Gerrhosaurus validus validus A. Smith, 1849 in South Africa

Thelandros schusteri Hering-Hagenbeck, 2001, Thelandros luciusi Hering-Hagenbeck, 2001, Thelandros boomkeri Hering-Hagenbeck, 2001, Tachygonetria bainae Hering-Hagenbeck, 2001, Tachygonetria chabaudi Hering-Hagenbeck, 2001 and Tachygonetria petterae Hering-Hagenbeck, 2001 from the plated lizard, Gerrhosaurus validus validus A. Smith 1849 from three localities in the north-eastern region of South Africa are redescribed. Classification keys are available only for the males of the species and because male and female nematodes in copula were not observed in this study as well as the similarity of the females, it was not possible to identify the females to the species level. Thelandros schusteri, Thelandros boomkeri and Thelandros luciusi were provisionally paired with female Type E, Tachygonetria bainae with female Type C, Tachygonetria chabaudi with female Type A and Tachygonetria petterae with female Type D. Female Types B and F could not be paired. The richness and composition of species of the Pharyngodonidae of Gerrhosaurus validus validus is close to that of tortoises and differs from the pharyngodonid fauna of the insectivorous lizards that have been studied. In the latter, only the genera Spauligodon, Skrjabinodon and Parapharyngodon were recovered. The pharyngodonid fauna of Gerrhosaurus validus validus seems to have originated by capture from local herbivorous reptiles. The three Tachygonetria spp. most closely resemble forms in South African tortoises. The three Thelandros spp. redescribed here not only show strong similarities to those of herbivorous Agama spp., but also to those parasitic in tortoises and could have been acquired from either.     

Neothada hades N.sp. from South Africa,with notes on the genus and a key to the species (Nematoda: Tylenchidae)

Neothada hades n.sp. from South Africa is characterized by the posession of small but distinct stylet knobs, 149-175 body annules intersected by 14 longitudinal lines (incisures), protruding lateral fields marked by four incisures, and an elongate-conoid tail with bluntly rounded tip. Reasons are given why N. canceilata (Thorne 1941) and N. tatra (Thome & Malek 1968) are regarded as two distinct species, and why N. canceilata apud Andrassy, 1982 is regarded as distinct from Thome’s species. Andrassy’s species is renamed N. andrassyi n.sp. A key is presented for the six recognized species of Neothada.