Thursday, October 21, 2021

[Ichthyology • 2021] New Records and Redescription of Labracinus atrofasciatus (Herre, 1933) (Teleostei: Pseudochromidae)


Labracinus atrofasciatus (Herre, 1933)

in Gill, Sorgon, Brun & Tea, 2021.
RAFFLES BULLETIN OF ZOOLOGY. 69 

Photographs by V. Brun.

Abstract
 The pseudochromid Labracinus atrofasciatus (Herre, 1933) is redescribed based on examination of the holotype from Culion, Calamian Islands, and three newly acquired non-type specimens from a fish landing site in Barangay Sandoval, Municipality of Taytay, northern Palawan, Philippines. Prior to this, the species was known only from the holotype; from a photograph of a putative female taken in Lajo Island, Busuanga, Calamian Islands; and from observations at Lajo Island and Tangat Island, Calamian Islands. The new specimens from Macuao Island appear to be males, and their live colouration is reported here for the first time. We also briefly comment on the restricted distribution of other pseudochromids and coral-reef fishes in the Palawan region of the Philippines.

 Key words. dottyback, Philippines, endemic, Palawan, Calamian Islands, Culion, Taytay


Freshly dead Labracinus atrofasciatus specimens from Macuao Island, northern Palawan, Philippines.
A, PNM 15645, 146.5 mm SL; B, PNM 15646, 142.0 mm SL; C, AMS I.49470-001, 134.4 mm SL.
Photographs by V. Brun (A) and K. E. S. Sorgon (B, C).

Two specimens of Labracinus atrofasciatus (approximately 150 and 190 mm TL) amongst catch of other reef fishes at a fish landing site in Barangay Sandoval, Municipality of Taytay, northern Palawan, Philippines. Specimens not retained.
Photograph by V. Brun.

Labracinus atrofasciatus (Herre, 1933) 
Black-barred dottyback

Diagnosis. Labracinus atrofasciatus differs from congeners in having a series of narrow, dark blue to black oblique bars on the body. It also differs in having relatively high numbers of horizontal scale rows above the anal-fin origin (24–27 + 1 + 4–5 = 30–33), pseudobranch filaments (22–24), and circumpeduncular scales (30–32).

Etymology. The specific epithet is derived from the Latin ‘atrum’, black, and ‘fascia’, band, in reference to the striking markings on the body of this species. Labracinus atrofasciatus is known locally as ‘akot’ in Cuyonon, a language spoken mostly in Cuyo Islands and coastal areas of Palawan in the Philippines, where it shares the local name with the congeneric L. cyclophthalmus. 

Habitat and distribution. We extend the known distribution of L. atrofasciatus from Culion in the Calamian Islands southward to Taytay, Palawan (Fig. 4A). ...

Map of the Philippines, showing distribution records for selected species of pseudochromids endemic to the Calamian Islands and Palawan regions.
A, Labracinus atrofasciatus, photograph of PNM 15645; B, Pseudochromis colei, photograph of aquarium specimen (not retained);
C, P. eichleri, photograph of AMS I.45651-001 (paratype); D, Manonichthys scintilla, photograph of USNM 382744 (paratype).
Photographs by V. Brun (A), Y. K. Tea (B), G. R. Allen (C), and J. T. Williams (D).

A, putative female of Labracinus atrofasciatus, in situ photograph taken in Lajo Island, Palawan, Philippines;
B, holotype of L. atrofasciatus, CAS-SU 25518, 105.5 mm SL holotype (image adapted from Gill, 2004). Note the posterior dorsal-fin spot and faint vertical bars in both specimens.
Photographs by G. R. Allen & M. V. Erdmann (A) and P. Crabb (B).



Anthony C. Gill, Kent Elson S. Sorgon, Victor Brun and Yi-Kai Tea. 2021. New Records and Redescription of Labracinus atrofasciatus (Herre, 1933) (Teleostei: Pseudochromidae). RAFFLES BULLETIN OF ZOOLOGY. 69; 438–447.