First record of the river goby Glossogobius callidus (Smith 1937) from Malawi

Abstract

In preparation for a new Red Data list for southern African freshwater fishes, the distributions of all species have been mapped, based primarily on museum records. The map prepared for Glossogobius callidus (Smith 1937) showed a record for the Lower Shire River in Malawi, a tributary of the Lower Zambezi. As this species had not, to my knowledge, previously been recorded from Malawi, and since the record does not appear in the current regional fish atlas (Scott et al. 2006), the specimen in the SAIAB collection (SAIAB 42108) was checked. It was caught on rod and line at Sucoma Sugar Estate (16°17’S, 34°55’E, Nchalo, in 1992) (Figure 1) and was sent to me for identification by the Angling Society of Malawi. Not realising that the distribution of G. callidus extended much further north, and also further inland, than is shown in Skelton’s (1993) map, a fact not known until Greenwood (1994) drew attention to the existence of the species in the Limpopo system, I identified the specimen as G. giuris (HamiltonBuchanan 1822), a widespread species in south-eastern African freshwaters. It was deposited in the SAIAB collection under that name, but was subsequently re-identified as G. callidus and re-labelled. I have not been able to ascertain who re-examined the specimen and corrected the identification, as there is no comment on the label or in the database. Glossogobius giuris also occurs in the Lower Shire and in Lake Chiuta (Figure 1), at the headwaters of the LugendaRovuma system on the Malawi-Mozambique border. The relative abundance of the two species in the Lower Shire River is unknown. Distinguishing features between the two species were discussed and illustrated by Greenwood (1994). A third species, Glossogobius tenuiformis Fowler 1934, was described from Lake St Lucia in South Africa. Currently a synonym of G. giuris, this species is now recognised as valid (H Larson, Museum and Art Gallery of the Northern Territory, Darwin, Australia, unpublished data, which includes a key to the Western Indian Ocean Glossogobius species). It is known only from the Zotsha River mouth, south of Port Shepstone, to Richards Bay.