XXVI.—Natural history notes from H.M. Indian Marine Survey Steamer ‘Investigator,’ Commander R. F. Hoskyn, R.N., commanding.—No. 16. On the Bathybial Fishes collected in the Bay of Bengal during the season 1889–90

Description of a new perchlet, Chelidoperca formosa, from southwestern Taiwan (Peciformes: Serranidae)

A new perchlet species is described on the basis of four specimens collected from southwestern Taiwan. It is similar to congeners with relatively few lateral-line scales (35-38) and can be distinguished by having third to sixth dorsal-fin spines notably long; eighth and ninth dorsal-fin spines notably short; developed gill rakers 1 + 7-8; scale rows between lateral line and sixth dorsal-fin spine 4 (the dorsalmost half-sized); tip of upper corner of caudal fin reddish; four reddish bands midlaterally on body with groups of melanophores in these bands. DNA barcoding analysis reveals the new species is a distinct lineage and closest to Chelidoperca microdon. The average interspecific genetic distance calculated by the K2P model is 15.4%, whereas the mean distance from the new species to C. microdon is 18.3%. The inferred phylogenetic tree supports monophyly of Chelidoperca. Including the new species, six nominal species of Chelidoperca are recognized in Taiwanese waters.

Revision of the bathyal cusk-eels of the genus Bassogigas (Ophidiidae) with description of a new species from off Guam, west Pacific Ocean

The bathyal genus Bassogigas (Teleostei: Ophidiidae) is revised based on 25 specimens, 18 from the west Atlantic Ocean and seven from the Indo-west Pacific Ocean. One specimen, from off Guam, west Pacific Ocean, represents a new species, Walker's cusk eel Bassogigas walkeri. The other 24 specimens all belong to the type species, Gills cusk eel Bassogigas gillii. A comparison between the Atlantic and the Indo-west Pacific Ocean specimens of B. gillii showed no differences in meristic and morphometric characters, but in two of the Indo-west Pacific Ocean specimens the sagittal otolith varied somewhat from the remaining specimens. The two Bassogigas species differ in the length of the lateral line, the number of scales in the midline of the body, the form of the median basibranchial tooth patches and in the thickness of the otolith.