Pseudempleurosoma haywardi sp. nov. (Monogenea: Ancyrocephalidae (sensu lato) Bychowsky & Nagibina, 1968): An endoparasite of croakers (Teleostei: Sciaenidae) from Indonesia

Abstract

An endoparasitic monogenean was identified for the first time from Indonesia. The oesophagus and anterior stomach of the croakers Nibea soldado (Lacépède) and Otolithes ruber (Bloch & Schneider) (n = 35 each) sampled from the South Java coast in May 2011 and Johnius amblycephalus (Bleeker) (n = 2) (all Sciaenidae) from Kedonganan fish market, South Bali coast, in November 2016, were infected with Pseudempleurosoma haywardi sp. nov. Prevalences in the first two croakers were 63% and 46%, respectively, and the two J. amblycephalus harboured three and five individuals. All three croakers represent new hosts for this monogenean genus. We provide infection rates, light microscopical observations, 3D confocal microscopical illustrations, and a morphometric comparison with all congeners. The new species differs in body size, the position and shape of the ovary and testes, and especially in the composition of the dorsal anchor complex, with the dorsal bar being anteriorly concave rather than planar or convex as in its congeners. The dorsal and ventral anchors of this new species are the longest in the genus, whereas the male copulatory organ is the smallest. The first DNA sequences for a member of this genus demonstrate the greatest similarity with endoparasitic freshwater monogeneans from African cichlid fishes. This suggests a freshwater origin for these marine endoparasitic monogeneans.

Endoparasitic Paradiplectanotrema klimpeli sp. nov. (Monogenea: Ancyrocephalidae) from the Greater Lizardfish Saurida tumbil (Teleostei: Synodontidae) in Indonesia

“…3). This methodology is found to be suitable to detect minor, often difficult to describe differences in the haptoral structures of these small monogeneans (also see Theisen et al 2017). The (sub-)generic (re-)descriptions of Diplectanotrema by Johnston and Tiegs (1922) and Price (1937) are based on the type species Diplectanotrema balistes (MacCallum, 1915) Johnston and Tiegs, 1922.…”

“…comm. 2017), all (re-) descriptions seem to have misinterpreted the anchor apparatus (discussion on Pseudempleurosoma in Theisen et al 2017), with D. priacanthi Lebedev, 1968 still awaiting re-examination in the future. The first adequate diagnosis for Pseudempleurosoma as well as Paradiplectanotrema were provided by Gerasev et al (1987).…”

“…However, while all hosts of Pseudempleurosoma spp. are associated with coastal waters and reefs, the host species of Paradiplectanotrema are deep-water fishes (see Table 2 here and Table 3 in Theisen et al (2017)). …”

“…However, bottom-dwelling schooling fish often ingest and disgorge bottom material such as mud and sand while searching for food, which might be a possible way for transmitting the eggs and parasite infection to another host. Theisen et al (2017) sampled P. haywardi in May and July 2011 (dry sesason) off the South coast of Central Java, and again during sampling of P. klimpeli sp. nov. in November 2016 (rainy season) off South Bali.…”

“…Besides showing a simple life cycle, a posterior attachment organ called (opist)haptor, armed with clamps, anchors and/or hooks, is unique and differentiates the hermaphroditic Monogenea from other flatworms (Mehlhorn, 2001). Theisen et al (2017) shed light on the morphology of the often misinterpreted anchor apparatus of Pseudempleurosoma Yamaguti, 1965, presenting the first laser confocal images of a 'Diplectanotrema group' member. Within this group (Diplectanotrema Johnston and Tiegs,for Paradiplectanotrema.…”