Cytochrome oxidase I sequences reveal possible cryptic diversity in the cosmopolitan symbiotic copepod Nesippus orientalis Heller, 1868 (Pandaridae: Siphonostomatoida) on elasmobranch hosts from the KwaZulu-Natal coast of South Africa

Over the past decade, numerous molecular phylogenetic studies uncovered cryptic diversity within the Copepoda, yet very few investigations focused on symbiotic copepods. Here we report mitochondrial DNA cytochrome oxidase I diversity in the cosmopolitan elasmobranch symbiont Nesippus orientalis off the KwaZulu-Natal coast of South Africa. Analysis of partial COI sequences of copepods sampled from a diversity of shark hosts, revealed the presence of two divergent clades. Diversity within the clades does not appear to be structured based on host species, host individual, geographic locality or time of sampling. However, divergence between the two clades seems to be related to host species. Phylogenetic analyses of representatives from the two clades, along with Nesippus spp., Caligus spp. and Lepeophtheirus spp. outgroups, further supports the distinction between the two clades. Future molecular phylogenetic investigations of widespread copepod symbionts most likely will reveal far greater levels of biodiversity than currently recognized.     

Spiders as potential indicators of elephant‐induced habitat changes in endemic sand forest,Maputaland, South Africa

Elephant impacts on spider assemblages, and the potential use of spiders as indicators of habitat changes was assessed in central Maputaland, South Africa. Three habitats, namely undisturbed sand forest, elephant disturbed sand forest and mixed woodland, were sampled. To ensure a thorough representation of all spider guilds, spiders were collected by tree beating, sweep netting, active searching, leaf litter sifting and pitfall traps. In total, 2808 individual spiders, representing 36 families, 144 determined genera and 251 species were collected. Spider abundance was highest in the undisturbed sand forest (n = 1129, S = 179), followed by elephant disturbed sand forest (n = 1006, S = 165) and mixed woodland (n = 673, S = 171). Assemblages of the two sand forests were more similar than to the mixed woodland assemblage. Active hunting species were indicators of the more open vegetation of elephant disturbed sand forest (six active hunters, no web‐builders) and mixed woodland (ten active hunters, one web‐builder), whereas web‐builders are indicators of the dense, complex vegetation structure of undisturbed sand forest (six web‐builders, three active hunters). Elephant‐induced changes to the vegetation structure in this high diversity, high endemism region result in changes in the composition of spider assemblages, and may need to be mitigated by management intervention.     

Branchotenthes robinoverstreeti n. gen. and n. sp. (Monogenea: Hexabothriidae) from gill filaments of the bowmouth guitarfish,Rhina ancylostoma (Rhynchobatidae), in the Indian Ocean

Branchotenthes robinoverstreeti n. gen. and n. ap. (Monogenea: Hexabothriidae) infects the gill filaments of the bowmouth guitarfish, Rhina ancylostoma Bloch and Schneider, 1801 (Rhynchobatidae) in the southwest Indian Ocean off Trafalgar, South Africa. The new species is most easily distinguished from other hexabothriids by the combination of having a symmetrical haptor, C-shaped haptoral sucker sclerites that are approximately equal in size, haptoral suckers that are equal in size and arranged in 3 tandem pairs that each straddle the longitudinal axis of the haptor, glandular-walled vasa efferentia that are dilated in the distal portion and unite medially before connecting to the vas deferens, a thick-walled male copulatory organ with an oblong proximal portion and an unarmed and finger-like distal portion, parallel vaginae that each possess a thin-walled and sperm-filled proximal portion that is strongly sinuous as well as a thick-walled and musculoglandular distal portion that extends sinuously anteriad, and an egg with a filament at each end. This is the first report of a hexabothriid from asharkfin guitarfish (Rhynchobatidae). A key to the genera of Hexabothriidae is provided.     

Use of DNA fingerprinting in planning a breeding program for the riverine rabbit (Bunolagus monticularis)

The riverine rabbit (Bunolagus monticularis) is an endangered and endemic species found within a small geographic range in semiarid southern Africa. A captive breeding program has been initiated for reintroducing rabbits into suitable but vacant habitat. DNA fingerprinting was used to identify individuals within a captive group suitable for inclusion in a larger captive breeding program. This methodology allowed the ranking of suitabilities of these individuals, and the results emphasize the need to capture wild rabbits over a wide geographic area for setting up a larger founder population. A statistical technique for inferring linkage between fingerprint probes was used. Fingerprinting methodology allowed a genetic basis for planning the captive breeding program. © 1994 Wiley-Liss, Inc.     

Neoalbionella izawai n. sp. from the smallfin gulper shark Centrophorus moluccensis Bleeker and additional host records for N. etmopteri (Yamaguti, 1939) off South Africa

Neoalbionella Özdikmen, 2008 comprises 10 accepted species, which all infect sharks of Squaliformes and Carcharhiniformes. Adult females belonging to species of Neoalbionella, based on the maxillule palp armed with three setae and the maxilliped subchela claw with only one secondary denticle, were collected from sharks off the coast of South Africa. Neoalbionella izawai n. sp. collected from the anterodorsal part of the spiracle opening of Centrophorus moluccensis Bleeker differs from its congeners by having maxillae that are separated except at the tapering tips where they are fused and that are longer than the trunk, uropods originating from the pointed posterior margin of the trunk and that are well developed, and maxillipeds without an additional spine at the base of the subchela barb. Neoalbionella etmopteri (Yamaguti, 1939) is herein reported from two new hosts (Etmopterus spp.) off South Africa.

     

<Emphasis Type="Italic">Trebius benzi</Emphasis> n. sp. (Siphonostomatoida: Trebiidae) infecting <Emphasis Type="Italic">Squalus acutipinnis</Emphasis> Regan off South Africa

Trebius Krøyer, 1838 currently consists of 15 accepted species all infecting elasmobranchs. Apart from two species, i.e. T. caudatus Krøyer, 1838 and T. latifurcatus Wilson, 1921, that have been reported from ten and eight host species, respectively, the other 13 species have each been reported from only one or two host species. Trebius benzi n. sp., collected from Squalus acutipinnis Regan, is described and illustrated after examination through stereo- and compound microscopes. This species can be distinguished from the other known species by a combination of characters including an abdomen that is shorter than the genital complex, a maxillule with an endite that consists of a single-tined dentiform process, sternal furca tines that are blunt and as long as the base, and the innermost spine of the last exopodal segment of leg 1 the shortest.     

The isolation of lymphocyte mitochondria and their regulation of extramitochondrial free Ca2+ concentration.

1. A method for the isolation of functionally intact mitochondria from lymphocytes is described. It involves digitonin breakage of the plasma membrane, followed by differential centrifugation. The yield was 36 mg of mitochondrial protein/200 g of pig mesenteric lymph node (6 mg of mitochondrial protein/10(9) lymphocytes). The mitochondrial had a respiratory-control ratio of 2--3.5 with succinate as substrate. 2. Ca2+ transport by these mitochondria was investigated. They were able to regulate the extramitochondrial free [Ca2+] very precisely, by buffering any displacements from the steady-state. The exact extramitochondrial free [Ca2+] of this steady-state depended on the conditions of incubation. In a medium designed to resemble the cytoplasmic environment, with added Ca2+, lymphocyte mitochondria maintained a steady-state free [Ca2+] of 0.63 microM (pCa of 6.2). The rates of Ca2+ uptake and efflux under these conditions, with both lymphocyte and liver mitochondria, were very much lower than those in a less complex medium. 3. Lymphocyte mitochondria were shown to possess an Na+-independent Ruthenium Red-insensitive efflux pathway similar to that of liver mitochondria. Ruthenium Red totally inhibited the electrophoretic uniporter. Although Na+ had no effect on the steady-state maintained by lymphocyte mitochondria, they were shown to possess an Na+/H+ antiporter.     

Nesippus orientalis Heller, 1868 (Pandaridae: Siphonostomatoida): descriptions of the adult, young and immature females, a first description of the male and aspects of their functional morphology

Nesippus orientalis Heller, 1868, a cosmopolitan species found in the mouth and on the gill-arches of a number of shark hosts, is distinguished from other species by the presence of dorsal plates on the fourth thoracic segment. Specimens were collected from various sharks caught in the nets of the Natal Sharks Board, off the coast of KwaZulu-Natal, South Africa. Collected specimens were preserved in 70% ethanol and studied using the wooden slide technique and scanning electron microscopy. Careful examination of adult females revealed features previously not described in detail. Furthermore, some female specimens were still grasping the placoid scales of their hosts. These specimens showed how the maxillipeds are used to clasp the host. Immature, young females and males, some still attached to the young females, were also collected. The males use their maxillipeds, which have a slightly different structure to those of the female, to hold onto the females.