A first for Southern Africa: description of a new Heterobothrium (Monogenea: Diclidophoridae) parasitizing the evileye pufferfish Amblyrhynchotes honckenii (Tetraodontiformes: Tetraodontidae)

Description of a new species, Pseudodiscocotyla mikiae n. sp. (Monogenea: Discocotylidae) parasitic on gills of Pristipomoides filamentosus from off Okinawa-jima island in Japan, with redescription of Pseudodiscocotyla opakapaka

Two species of Pseudodiscocotyla Yamaguti, 1965 (Monogenea: Discocotylidae) were collected from crimson jobfish Pristipomoides filamentosus (Valenciennes) (Perciformes: Lutjanidae) off Okinawa-jima island, southern Japan. Pseudodiscocotyla opakapaka is redescribed and represents the first Japanese record. A new species, Pseudodiscocotyla mikiae n. sp., differs from Ps. opakapaka in the absence of spines around the male genital pore, the shape of the vaginal pore, the presence of spines inside the vaginal pore, and the shape of the clamp. The locations of the male genital atrium and the vaginal pore in both species were similar, and the observed armament differences of the male copulatory organ are therefore presumed to establish reproductive isolation. The phylogenetic trees for the Mazocraeidea based on the partial 28S rDNA sequences were created using new sequences of Pseudodiscocotyla mikiae n. sp., and Discocotylidae formed a sister group with the species Diclidophoridae, Macrovalvitrematidae, and Plectanocotylidae. Pristipomoides filamentosus is widely distributed across the Indo-Pacific, and Pseudodiscocotyla mikiae n. sp. could share the distribution of the host.

The use of fish parasitic isopods as element accumulation indicators in marine pollution monitoring

Marine ecosystems are continuously under threat due to pollutants, which endanger marine biodiversity. The present study determines the potential use of the parasitic isopod, Cinusa tetrodontis Schjödte et Meinert, 1884, together with its fish host, Amblyrhynchotes honckenii (Bloch) for marine bioaccumulation monitoring. The concentrations of As, Cd, Cu, Mn, Ni, Pb, Se, and Zn were determined in muscle and liver tissues of infested and uninfested fish, and male and female parasites on the South African temperate south coast. The concentrations of Cu and Ni in C. tetrodontis differed significantly between two sampling sites, a near-pristine (Breede River Estuary, Witsand) and a more polluted site (harbour area in Mossel Bay). Mossel Bay isopods had higher concentrations of Ni, while Witsand isopods had higher concentrations of Cu. In contrast to fish hosts, parasitic isopods accumulated significantly higher levels of all elements except Cd. Most significant relationships between elements accumulated by C. tetrodontis and an increase of elements in fish tissues were seen in liver, rather than muscle tissue samples. Specimens of C. tetrodontis can be defined as good bioindicators for elements such as As, Cu, Mn, Ni, Pb, Se, and Zn, as they possess high bioaccumulation capabilities. This study addresses one of several future directions needed within environmental parasitology and highlights the importance of studying and utilising this host-ectoparasite model system.

Five new and two known species of Heterobothrium (Monogenea: Diclidophoridae) infecting puffers of the genus Takifugu from Japanese waters

Seven species of puffers of the genus Takifugu caught in Japanese waters were examined for monogeneans on the gills. Five new species of Heterobothrium (H. gotoi n. sp. from T. porphyreus, H. tabetai n. sp. from T. vermicularis, H. aljufailiae n. sp. and H. iwatai n. sp. from T. snyderi, H. matsubarai n. sp. from T. stictonotus) and two known species (H. praeorchis Bychowsky, Mamaev & Nagibina, 1976 from T. pardalis, T. chrysops and T. flavipterus and H. bychowskyi Ogawa, 1991 from T. flavipterus) were found and described. Heterobothrium tetrodonis of Iwata (1991) was synonymized with H. bychowskyi. Currently, a total of 11 species of Heterobothrium, including the seven species in this study, were recorded from nine species of Japanese Takifugu spp. Ten species excluding H. praeorchis were found from a single host species, suggesting that they are highly host-specific and have co-evolved with the host Takifugu spp. Tagia Sproston, 1946 is synonymized with Heterobothrium. Earlier divergence of Heterobothrium of tetraodontid puffers in Diclidophoridae was suggested by the large subunit ribosomal DNA (rDNA) analyses, and interspecific relationships in this genus inferred from the internal transcribed spacer region of rDNA well corresponded to those inferred from their morphology and adhesive mode to the gills. Including the five new species and synonymization of Tagia with Heterobothrium, the genus Heterobothrium now comprises 19 species.