Susan M. Dippenaar

Reported Siphonostomatoid Copepods Parasitic on Marine Fishes of Southern Africa

Worldwide there are more than 12000 species of copepods known, of which 4224 are symbiotic. Most of the symbiotic species belong to two orders, Poecilostomatoida (1771 species) and Siphonostomatoida (1840 species). The order Siphonostomatoida currently consists of 40 families that are mostly marine and infect invertebrates as well as vertebrates. In a report on the status of the marine biodiversity of South Africa, parasitic invertebrates were highlighted as taxa about which very little is known. A list was compiled of all the records of siphonostomatoids of marine fishes from southern African waters (from northern Angola along the Atlantic Ocean to northern Mozambique along the Indian Ocean, including the west coast of Madagascar and the Mozambique channel). Quite a few controversial reports exist that are discussed. The number of species recorded from southern African waters comprises a mere 9% of the known species.

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.

Estimated Molecular Phylogenetic Relationships of Six Siphonostomatoid Families (Copepoda) Symbiotic on Elasmobranchs

Members of the Siphonostomatoida are associated with either invertebrates or vertebrates. Even though the interfamilial relationships within the Siphonostomatoida are unresolved, it has generally been assumed that those members parasitic on vertebrates form a derived and monophyletic group. Eleven of the families symbiotic on vertebrates have been reported from elasmobranchs. One nuclear genetic marker (18S rDNA) and two partial mitochondrial markers (16S rDNA and COI) were used to estimate the phylogenetic relationship among six families symbiotic on elasmobranchs. The estimated molecular topologies using maximum likelihood, parsimony (unweighted and weighted), and Bayesian analyses are mostly similar. The six families investigated grouped into two major clades, with Kroyeriidae, Caligidae, Pandaridae, and Dichelestiidae in one clade, and Eudactylinidae and Sphyriidae in the other. The molecular topologies are compared with the previous morphological topology and present some support for some of the proposed relationships and alternative hypotheses in the areas of conflict. Valuable information obtained from the study is the indication that the genes used are informative at this level of investigation and can therefore be used in more elaborate future studies.

Spatial distribution of Nemesis lamna Risso 1826 (Copepoda: Siphonostomatoida: Eudactylinidae) on the gills of white sharks Carcharodon carcharias off KwaZulu-Natal, South Africa

The selection of a specific site of attachment by a copepod parasite is determined by a set of mostly unknown factors. The spatial distribution of Nemesis lamna on the gill filaments of white sharks Carcharodon carcharias was investigated. The complete set of left gills of 11 hosts was examined and the location, orientation and gender of each copepod noted. N. lamna exhibited a prevalent of 100% and a mean intensity of 74 individuals per shark. There was no relationship between the size of the host and the number of filaments per hemibranch or the number of N. lamna attached to the host. Only 13.7% of the variation in number of individuals per hemibranch was due to the variation in the number of filaments per hemibranch, and most specimens (33.6%) were collected from the fourth holobranch. Most N. lamna (86.5%) were attached to the dorsal and ventral quarters of the hemibranchs, of which 63.1% were attached to the outer hemibranchs. There was no site preference in terms of their position on the filaments, but most were attached with their cephalothoraces facing the incoming respiratory water flow, especially those attached to the proximal quarter. The N. lamna infrapopulations on white sharks are aggregated, which is probably due to the need to reproduce.

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.

New Locality Records for Dermophthirius carcharhini (Monogenea: Microbothriidae) and Dermophthirius maccallumi and a List of Hosts and Localities for Species of Dermophthirius

Abstract We report Dermophthirius carcharhini (Monogenea: Microbothriidae) from the skin of a dusky shark, Carcharhinus obscurus (Carcharhinidae), in the southwest Indian Ocean off Umhlanga Rocks, South Africa, and Dermophthirius maccallumi from the skin of 2 bull sharks, Carcharhinus leucas, in the northern Gulf of Mexico off Cat Island, Mississippi, U.S.A. No previous report exists of a microbothriid from the western Indian Ocean or from off southern Africa or of D. maccallumi from beyond the vicinity of the Lake Nicaragua–San Juan River system. We also provide a list of hosts and localities for members of Dermophthirius.

Two new species of Pupulina van Beneden, 1892 (Copepoda: Siphonostomatoida: Caligidae) from mobulid rays off South Africa

The caligid genus Pupulina van Beneden, 1892 currently has three accepted species. Two new species, Pupulina cliffi n. sp. and P. merira n. sp., are described from Mobula kuhlii (Müller & Henle) and M. eregoodootenkee (Bleeker) (Mobulidae) caught along the east coast of South Africa. Pupulinacliffi can be distinguished from all the other species by the absence of posterolateral processes on the genital complex, whereas P. merira has very short, rounded posterolateral processes on the genital complex compared to the three previously known species. Additionally, P. merira is the only species with the abdomen only about two-thirds the length of the genital complex and the caudal rami about the same length as the abdomen. A dichotomous key to distinguish the five species of Pupulina is provided.

Kroyeria deetsi n.sp. (Kroyeriidae:Siphonostomatoida), a parasitic copepod infecting gills of spinner sharks, Carcharhinus brevipinna (Müller & Henle, 1839), in the Indian Ocean

Kroyeria deetsi n.sp. (Kroyeriidae: Siphonostomatoida) is described from both sexes collected from the gills of spinner sharks, Carcharhinus brevipinna (Müller & Henle, 1839), captured in the Indian Ocean off the coast of South Africa. Kroyeriadeetsi n.sp. can easily be distinguished from all of its congeners because the third endopod segments of legs 1–4 of the new species are about twice (legs 1, 2 and 4), or more than twice (leg 3), as long as the corresponding second endopod segments in the female.

Biodiversity and studies of marine symbiotic siphonostomatoids off South Africa

Current knowledge of the biodiversity of the symbiotic marine siphonostomatoids from South African waters (136 species) is sparse compared to that globally (1 388 species). The difference is especially apparent when taking into account the diversity of fish (more than 2 000 species) and invertebrates (approximately 12 914 species) found in South African waters, all of which are all potential hosts of symbiotic siphonostomatoids. Most reports of symbiotic siphonostomatoids from South African waters are from Chondrichthyes and represent 80% of the currently known families and about 66% of the known genera. Taxonomic studies on the siphonostomatoids also provide information about their morphology, biology, habitat preference and host association, as well as the distribution of species and their associated host taxa. Molecular analysis, especially sequencing, provides additional information on the existence of cryptic species and population structure, but has high financial costs and a very low success rate in DNA isolation and PCR amplification. Reported declines in abundance of piscivorous fish species, for example, as a result of fishing pressure, with possible synergistic effects of environmental changes, and also the reported potential effects of anthropogenic and climate change on the broader coastal biota, may result in the loss of siphonostomatoid species before they can be described. Furthermore, in South Africa, there is a lack of professional taxonomists to study poorly known groups and this situation will not improve while research emphasis remains on commercially important groups and while taxonomic studies are not recognised for their value in research programmes.

Description of the adult female and male of Naobranchia kabatana n. sp. (Copepoda: Lernaeopodidae) from Muraenesox bagio (Hamilton) (Muraenesocidae) caught in the Indian Ocean off South Africa.

Naobranchia Hesse, 1863 is a genus of the family Lernaeopodidae. This report presents an illustrated description of the adult female and male of a new species of this genus collected from the gill filaments of Muraenesox bagio (Hamilton) (pike conger) caught off the coast of Richards Bay, KwaZulu-Natal, South Africa. Its morphological features were examined using light and scanning electron microscopy. Characteristic features of the female Naobranchiakabatana n. sp. include egg-sacs situated along most the length of the trunk, cephalothorax and trunk of about equal lengths, and egg-sacs, lacking distinct sclerotised bands, which meet at the posterior end of the body and usually obscure the abdomen and caudal rami in ovigerous specimens. The male has no division into the cephalothorax and trunk, resulting in an unsegmented body with a prominent genito-abdominal papilla in a subterminal position.