Cheilodipterus singapurensis Bleeker, 1860

Russell, Barry C., Fraser, Thomas H. & Larson, Helen K., 2010, Castelnau’S Collection Of Singapore Fishes Described By Pieter Bleeker, Raffles Bulletin of Zoology 58 (1), pp. 93-102 : 95

Cheilodipterus singapurensis Bleeker, 1860

Cheilodipterus singapurensis Bleeker, 1860c , is based on a specimen which was related to a coloured painting by Castelnau, No. 67 (Fig. 4), with notes “ Cheilodipterus singaporensis Cast. Blk octovittatus Cu ? Val nov. spec.”. The mouth is partly open and shows large teeth. In the original Latin description, Bleeker (1860c) lists a single specimen of 149 mm total length (TL) and in the Dutch remarks he refers to another specimen of 119 mm TL. By 1874 Bleeker had added three more specimens and modified his description. A figure was provided by Bleeker (1875 – 1876 b: Pl. 35) in the Atlas. No changes were made to the description or remarks in 1876 from the additions in 1874. The descriptions by Bleeker, his figure and Castelnau’s painting do not show a black mark in the area of the anal and genital openings. Bleeker’s (1875 – 1876) figure was based on the juvenile colour pattern, probably from one of the smaller specimens. Gon (1993) provided the most recent revision of Cheilodipterus and recognized C. singapurensis as a valid species.

Although Gon listed Bleeker’s material, RMNH 5619 with three specimens, no types are mentioned or discussed. Ernest A. Lachner examined Bleeker’s material in 1956. He recorded four specimens present, one with a “conspicuously dark vent” (Lachner original notes). Four specimens were present when Fraser examined the lot in 1972. The largest specimen in the lot is about 144 mm TL not 149 mm. Martin Boeseman (in litt.) suggested that Bleeker may have made a 5 mm error reading his ruler, the printer misread a 9 for a 3, or the holotype was in the second lot of the Auction Catalog and went elsewhere, or is lost .

We regard the largest specimen as the probable holotype and one of the two smaller specimens mentioned by Bleeker is a paratype. The third specimen has no type status. No Bleeker specimen has been reported at the British Museum, another possible repository for the specimen. The specimen with the dark vent was identified as Cheilodipterus truncatus (139 mm TL) and removed to RMNH 26674 in 1972. While there are two interpretations of the significance of the blackish vent ( Lachner, 1953; Gon 1993), neither Bleeker’s written descriptions nor Castelnau’s figure provide any evidence that they observed this colour pattern. We conclude that Castelnau’s figure of an adult was used appropriately by Bleeker.