Environmental Biology of Fishes 45:150,1996 .©1996 Kluwer Academic Publishers. Printed in the Netherlands .

Threatened fishes of the world : Sandelia bainsii Castelnau, 1861(Anabantidae)

Jim A. CambrayAlbany Museum, Somerset Street, Grahamstown, 6140 South Africa

Common names: Eastern Cape rocky (E), Oos-Kaapse kurper(Afrikaans) .Conservation status : Vulnerable (South African Red Data Book- Fishes, Skelton 1987) .Identification : One of two species in the genus Sandelia which isendemic to South Africa . Both species have a smooth (non-spi-nous) edge to the lower half of the gill cover and a greatly re-duced air-breathing organ relative to other members in the fam-ily Anabantidae . D XV-XVI + 9-10, A VII-VII + 9-10, LL 30-32,22 scales around caudal peduncle. The gill cover has 2 spines separatedby a deep membrane-covered notch . The caudal fin is truncate and tassellated . Large mouth with sharp, conical teeth. Large eyes locatedforward on head. Olive or grey-brown with scattered flecks and spots, single grey bar behind eye, breeding males turn dark and developvisible ctenii on cheek scales (contact organs) . Reaches 260 mm SL. Drawing of an adult male by Penny Meakin .Distribution: Restricted to the Eastern Cape (32°34' to 33°33'S; 26°06' to 27°35'E) of South Africa with limited distribution in severaltributaries of the Buffalo, Keiskamma, Great Fish and Kowie river systems . Recent collections have confirmed earlier reports of a smallpopulation in the Nahoon River . Abundance: Dwindling numbers in most populations . Recent surveys along the Kowie system revealedonly 6 specimens after 4 days of surveying. In a former prime Great Fish River habitat only introduced sharptooth catfish, Clariasgariepinus, were collected. In the Tyume River, a tributary of the Keiskamma River, the S . bainsii population is small and vulnerable tolocal extinction . Habitat and ecology : The Eastern Cape Rocky occurs in rocky streams, wedges under rocks or other objects facingupstream waiting for insects, crabs or small fish to come into range. This species is sedentary. Males grow faster, live longer and reach alarger size than females . Reproduction: Sandelia bainsii mature in their second year, d d at 80-90 mm SL and 4 9 at 60-69 mm SL, breedin summer, October to February, which coincides with the rainy season and spawns several times per season . The males guard the eggs asdo S. capensis males, and a spawning site is prepared by the male . The eggs are adhesive, 1 .3 mm in diameter and have a small oil globule of0.6 mm in diameter. At 22-23° C the embryos hatch in less than 2 days and are 3 .4 mm TL . Threats: The species is threatened by poorwater quality, invasive alien fish and plants, loss of habitat due to water abstraction and damming . These are common threats to manyfreshwater fish species but the limited geographical range of S. bainsii and their small population size exacerbates these threats . They arealso very vulnerable to angling pressure . Conservation action: Immediate action is needed in the remaining habitats of S. bainsii. There isone reserve which has been specifically set aside for this species, the Blaauwkrantz Nature Reserve, managed by the Algoa RegionalServices Council . The reserve is situated on the Bloukrans River, Kowie River system . The reserve receives enriched waters from up-stream urban and rural areas which has resulted in the quick growth of an introduced water plant, Azolla filiculoides, which completelyalters the aquatic habitat . S. bainsii appears to breed well in ponds so that captive propagation may not be a problem . Conservation actionshould be focused on natural habitat restoration and conservation . Farm dams along the system should be used as breeding and refugeareas . Conservation recommendations : Further research is required on the spawning requirements of the species and the tolerance of thisspecies to increasing salinity and eutrophication levels . Remarks: The remaining habitats of S. bainsii require urgent conservation atten-tion . Good sanctuary areas should be located high up in the rivers where the fish naturally occurs so as to avoid many of the negativeimpacts which occur lower in the river systems, such as poor water quality, excessive water abstraction and alien predatory fish species .

Cambray, J.A . 1981 . The Eastern Cape rocky (Sandelia bainsii) . The Naturalist 25(1) : 28-30 .Cambray, J.A. 1990 . The early ontogeny of the Cape kurper, Sandelia capensis (Pisces : Anabantidae) . Ann. Cape Prov. Mus. (Nat . Hist .)

18(8):159-182 .Mayekiso, M. & T. Hecht. 1988a . Age and growth of Sandelia bainsii Castelnau (Pisces: Anabantidae) in the Tyume River, eastern Cape

(South Africa) . S. Afr. J . Zool. 23 : 295-300 .Mayekiso, M . & T. Hecht . 1988b . Conservation status of the anabantid fish Sandelia bainsii in the Tyume River, South Africa . S. Afr. J .Wildl. Res . 18 :101-108 .

Skelton, PH. 1987. South African Red Data Book - Fishes. S. Afr. Nat . Sci . Prog. Rep. No . 137 .199 pp .