Trochopus martydeveneyi n. sp. (Monogenea) infecting the pectoral fins of the southern African endemic Cape gurnard, Chelidonichthys capensis in Table Bay, and the proposal of Trochopus lawleri n. sp. for T. hobo from Australia.

Trochopus martydeveneyi n. sp., a large, elegant species is described from the dorsal surface of the pectoral fins of captive Cape gurnard, Chelidonichthys capensis (Cuvier), at Two Oceans Aquarium, Cape Town, originally collected from Table Bay, South Africa in 2007. The host microhabitat for T. martydeveneyi n. sp. is uncharacteristic for Trochopus species, which are generally known from the gills, and less so from the skin of the body of their hosts. This new species is unique among the known Trochopus species, possessing a large, dark-staining gland on each of the two testes, presumably to produce the contents of the spermatophore plug that is visible in the vagina of two specimens. Two separate individual specimens of T. martydeveneyi n. sp. also presented with unilateral testicular atrophy, which is apparently rare in the Monogenea but considered a natural occurrence. Egg hatching and larval haptoral morphology are also provided. Trochopus lawleri n. sp. is proposed for Trochopus hobo sensu Lawler and Hargis (1968) from the gills of Chelidonichthys kumu (Cuvier) off Australia, and the monotypic Trochopella Euzet & Trilles, 1962 is synonymised with Trochopus Diesing, 1850. The generic diagnosis is revised for Trochopus to incorporate new data, and information previously excluded.