Eggspots Elsewhere - Welt der Fische / World of Fishes

Haplochromis sp. “Ismailia”
In the aquarium males of this species attain a length of barely eight centimetres (SL). On
looking into the mouth the distinctive discoloration of the tooth pulp is immediately apparent
through the highly transparent enamel. Adult males and females can again be distinguished
by the different form of the tooth crowns in the outer series. Those of males are
predominantly unicuspid, those of females bicuspid, and in the latter there is sometimes a
flange visible on the longer cusp. The bicuspid teeth are more close-packed than the
unicuspid.
There are two possible reasons for this sex-linked tooth form. Firstly, males and females may
have different feeding habits. There is clear evidence for this in a work by SPATARU & GOPHEN
(1985) on Haplochromis flavii josephi, according to which males with a length of 70 - 80 mm
upwards feed largely on molluscs (probably snails by preference). In young males these
constitute only 20-30% of gut contents. According to the same study, females feed exclusively
on insect larvae (chironomids), amphipods, and oligochete worms. It would be interesting to
Jaw teeth of a male (above) and female (below) H. sp. “Ismailia” (in each case the anterior right-hand side). Striking features include not
only the variable form of the tooth crowns but also the different intervals between the individual teeth and the dark coloration of the
tooth pulp, possibly mineral in origin and not previously known from any other species.
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SCHRAML: Comparison of North African species