. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. 158 ANNALS OF THE SOUTH AFRICAN MUSEUM kunenensis is thus a western species confined to the Kunene and Okavango River systems as well as the upper Zambezi and its tributaries (Kafue, Luapala and Linyanti) as far north as approximately ITS latitude. The 'typical' form seems allied to Caelatura choziensis (Preston) from Lake Bangweulu and the Chambeshi River as illustrated by Haas (1936) and Mandahl-Barth (1972). Although the gonads were not examined histologically, dissection of a series of specimens from below the Rua
. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. 158 ANNALS OF THE SOUTH AFRICAN MUSEUM kunenensis is thus a western species confined to the Kunene and Okavango River systems as well as the upper Zambezi and its tributaries (Kafue, Luapala and Linyanti) as far north as approximately ITS latitude. The 'typical' form seems allied to Caelatura choziensis (Preston) from Lake Bangweulu and the Chambeshi River as illustrated by Haas (1936) and Mandahl-Barth (1972). Although the gonads were not examined histologically, dissection of a series of specimens from below the Ruacana Falls in the Kunene River showed that 58 per cent (25/43) were functional females with all four demibranchs modified to marsupia. The remaining 42 per cent (18/43) bore no sign of mar- supia and were considered males. The smallest female measured 25,6 X 17,8 x 12,0 mm. Although most marsupia were charged with embryos some contained sub-oval glochidia. The uniformly punctate valves of these glochidia were virtually equal in length and height (Fig. 4); the mean dimensions of six examples were 0,263 x 0,265 mm. No hooks were seen, although the glochidia may not have been fully developed. adductor mantle foot. 0 0-1 02 0-3 mm Fig. 4. Camera lucida drawing of a glochidium from an outer demibranch of Caelatura kunenensis (38,6 X 23,2 x 17,6 mm) from Ruacana Falls, Kunene River. Small leeches, Batraeobdella tricarinata (Blanchard) were found in the pallial cavities of 16,3 per cent (7/43) of Caelatura kunenensis from Ruacana on the Kunene River and a single emphemeropteran nymph (Baetidae: Cen- troptiloides ? sp.) was present in the pallial cavity of a specimen from the Zambezi at Katima Mulilo. Although this nymph is unlikely to be a 'pallial cavity' dweller, Centroptiloides nymphs are unusual among mayflies in being pre- daceous (F. M. Chutter, in lift. 31 January 1977). The presence of insect larvae inside bivalves was also noted by Beedham (1971) who found chironomid larvae b
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Keywords: ., bookauthorsouthafr, bookcentury1800, bookdecade1890, bookyear1898
