Luciosoma

L. bleekeri is most-easily distinguished from the congener L. setigerum, with which it is frequently confused, by absence (vs. presence) of a series of black spots on the lateral line scales.

The five species which currently comprise Luciosoma can be distinguished by elements of colour pattern. Popta described the colour pattern of L. pellegrinii as follows: body colour olive dorsally, with dark-edged scales, yellow ventrally; a lateral series of dark spots on the flank forming a midlateral band which extends onto the opercle but not the head; 4-8 blackish-brown, distinctly-separate spots on the lateral line; fins yellow; dorsal and anal fins with a blackish-brown band; anterior half of some pectoral-fin rays blackish-brown...

There is a fish of unknown geographical origin which matches the majority of diagnostic features for L. setigerum with the exception that the dark lateral stripe is absent in the anterior portion of the body and is not composed of interconnected spots. It is relatively common in the aquarium trade and included here as L. cf. setigerum until a confirmed identity is established.

This species is poorly known in general and is not present in the ornamental trade, although its name is widely misapplied to other Luciosoma species. Its congeners are mostly marketed as 'apollo shark', 'shark minnow', or similar, and often labelled with incorrect scientific names. Identification of the fish pictured here is based on Bleeker (1855, 1860) and Roberts (1989), plus drawings by Bleeker, thus...