Opecoelidae (Digenea) in northern Great Barrier Reef goatfishes (Perciformes: Mullidae)

Molecular characterisation of three species of Coitocaecum (Digenea: Opecoelidae) infecting Clinus superciliosus (Clinidae) in South Africa, with description of Coitocaecum brayi sp. n

The genus Coitocaecum Nicoll, 1915 is part of the most speciose digenean family, the Opecoelidae Ozaki, 1925, which is found globally in both freshwater and marine fishes. Fifteen opecoelid species have been reported from marine fishes in South Africa, yet only one species of Coitocaecum has been described from this region: Coitocaecum capense Bray, 1987. During an explorative study of the digeneans of the endemic, intertidal fish Clinus superciliosus (Linnaeus) from the Saldanha Bay area, Cape Town harbour, Hermanus, the Tsitsikamma section of the Garden Route National Park and Chintsa East in South Africa, a total of three distinct species of Coitocaecum were identified based on morphological and molecular (28S rDNA, ITS1-5.8S-ITS2 rDNA and COI mtDNA) data: the previously mentioned C. capense, Coitocaecum brayi sp. n. and a third, unnamed species. We provide the first molecular characterisation of species of Coitocaecum from South Africa, accompanied by detailed morphological descriptions. This study illustrates the importance of an integrated taxonomic approach, especially when studying species with similar morphology. These findings further emphasise the lack of information on the true diversity and molecular data for trematodes of marine fishes in South Africa, creating a great capacity for future explorative taxonomic studies and highlighting the use of intertidal areas for conducting such research.

What's in a name? Taxonomic and gender biases in the etymology of new species names

As our inventory of Earth's biodiversity progresses, the number of species given a Latin binomial name is also growing. While the coining of species names is bound by rules, the sources of inspiration used by taxonomists are an eclectic mix. We investigated naming trends for nearly 2900 new species of parasitic helminths described in the past two decades. Our analysis indicates that the likelihood of new species being given names that convey some information about them (name derived from morphology, host or locality of origin) or not (named after an eminent scientist, or for something else) depends on the higher taxonomic group to which the parasite or its host belongs. We also found a consistent gender bias among species named after eminent scientists, with male scientists being immortalized disproportionately more frequently than female scientists. Finally, we found that the tendency for taxonomists to name new species after a family member or close friend has increased over the past 20 years. We end by offering suggestions for future species naming, aimed at honouring the scientific community's diversity and avoiding etymological nepotism and cronyism, while still allowing for creativity in crafting new Latin species names.

Evidence for extensive cryptic speciation in trematodes of butterflyfishes (Chaetodontidae) of the tropical Indo-West Pacific

Molecular data from the cytochrome c oxidase subunit I (cox1) mitochondrial DNA gene and the second internal transcribed spacer (ITS2) nuclear rDNA region were used to test the current morphologically-based taxonomic hypothesis regarding species of Monorchiidae (Hurleytrematoides) from chaetodontid and tetraodontid fishes from six sites in the tropical Indo-West Pacific (TIWP): Heron and Lizard Islands off the Great Barrier Reef (GBR, Australia), Moorea (French Polynesia), New Caledonia, Ningaloo Reef (Australia) and Palau. The 16 morphospecies analysed differed from each other by a minimum of 55bp (9.1%) over the mitochondrial cox1 and 8bp (1.6%) over the ITS2 DNA regions. For two species, Hurleytrematoides loi and Hurleytrematoides sasali, specimens from the same host species in sympatry differed at levels comparable to those between pairs of distinct morphospecies for both cox1 and ITS2 sequences. We take this as evidence of the presence of combinations of cryptic species; however, we do not propose new species for these taxa because we lack identified morphological voucher specimens. For seven species, Hurleytrematoides coronatum, Hurleytrematoides deblocki, Hurleytrematoides faliexae, H. loi, Hurleytrematoides morandi, H. sasali and Hurleytrematoides sp. A, samples from some combinations of localities had base pair differences that were equal to or greater than differences between some pairs of distinct morphospecies for one or both cox1 and ITS2 sequences. For three species, H. coronatum, H. loi and H. morandi, one haplotype differed from every other haplotype by more than the morphospecies benchmark. In these cases morphological specimens could not be distinguished by morphology. These data suggest extensive cryptic richness in this genus. For the present we refrain from dividing any of the morphospecies. This is because there is a continuum of levels of intra- and interspecific genetic variation in this system, so that distinguishing the two would be largely arbitrary.