# Two new species of Microcotylidae Taschenberg, 1879 (Platyhelminthes: Polyopisthocotyla) parasitising Diplodus capensis (Teleostei, Sparidae) off South Africa

## TL;DR

This study discovered two new species of flatworm parasites in a type of fish off the South African coast.

## Contribution

The discovery of two new Microcotylidae species and the first genetic sequences of marine microcotylids from South Africa.

## Key findings

- Two new species of Microcotylidae were identified using molecular and morphological methods.
- Atriaster ibamba n. sp. is distinguished by hook characteristics around the genital atrium.
- Polylabris dassie n. sp. is unique due to its reproductive organ features.

## Abstract

Microcotylids have rarely been reported along the South African coast, even though the Microcotylidae is one of the dominant polyopisthocotylan families. The present study focused on elucidating the parasite diversity of the Cape white seabream, Diplodus capensis (Smith), from various localities along the South African coast. By combining molecular and morphological techniques, two previously undescribed species of the Microcotylidae were identified. Atriaster ibamba n. sp. primarily differs from its congeners by the number and size of the hooks surrounding the genital atrium. Polylabris dassie n. sp. has a single vagina and is unique to most others of this genus by having a smaller male copulatory organ, and by the shape of this organ. This is the first report of species of Atriaster from South Africa, as well as the first report of any polyopisthocotylan from D. capensis. The present study also contributes the first genetic sequences of marine microcotylids from South Africa.