Diplecogaster ctenocrypta Briggs 1955

Fricke, Ronald, Wirtz, Peter & Brito, Alberto, 2015, Diplecogaster tonstricula, a new species of cleaning clingfish (Teleostei: Gobiesocidae) from the Canary Islands and Senegal, eastern Atlantic Ocean, with a review of the Diplecogaster-ctenocrypta species-group, Journal of Natural History 50, pp. 731-748 : 743-746

Diplecogaster ctenocrypta Briggs 1955

Eastern Atlantic deep water clingfish

( Figures 7 – 9 )

Diplecogaster ctenocrypta Briggs 1955: 32 , figure 85 [Gran Canaria, Canary Islands, depth 90 fms (164.6 m); holotype ZMUC P9037 ]. Nielsen 1974: 85 (type catalogue). Dooley et al. 1985: 43 (Canary Islands; in checklist). Briggs 1990: 475 (Canary Islands). Hofrichter 1995: 156 – 159, figures 95 – 97. Hofrichter & Patzner 1997: 21. Fricke 2007: 68. Almada et al. 2008: 1151. Hanel et al. 2009: 166 (in checklist). Fricke et al. 2010: 92.

Material

ZMUC P9037 , holotype, 15.7 mm SL, Eastern Atlantic Ocean , Canary Islands, Gran Canaria, off La Luz, hard bottom with algae, 90 fms [165 m] depth, T . Mortensen, 28 March 1930.

Diagnosis

A species of Diplecogaster with 9 dorsal-fin rays, 8 anal-fin rays, 25 pectoral-fin rays, and 16 principal caudal-fin rays; pelvic disc with lateral papillae in region A; disc region B with 5 rows of papillae; principal caudal-fin rays 16; interorbital distance 5.4 in head length; distance between disc and anus 19% of SL; head and body pale, without bars or ocelli.

Description

Dorsal-fin ix; anal-fin viii; pectoral-fin xxv; caudal-fin xvi. Gill rakers on 3rd arch 18, very small, pointed.

Teeth small, conical, slightly recurved, in patches towards the front of each jaw, narrowing to a line of single teeth laterally.

Head lateral line system with 3 pores in nasal canal, 3 pores in postorbital canal, 1 pore in mandibular canal, and 2 pores in lacrymal canal ( Figure 9 ).

Head broad, depressed. Head length 39.5% SL (2.5 in SL). Maximum body depth 17.2% SL (5.8 in SL). Maximum head width 16.6% SL (6.0 in SL). Maximum (horizontal) orbit diameter 11.1% SL (3.5 in head length). Snout short, anteriorly straight ( Figure 7B ). Preorbital length 7.6% SL (5.2 in head length). Interorbital distance 7.3% SL (5.4 in head length). Upper jaw length 10.8% SL (3.6 in head length). Anus situated much closer to the anal-fin origin than to the disc; distance between disc and anus 19.1% SL, distance between anus and anal-fin origin 7.6% SL. Preanus length 66.8% SL (1.5 in SL). Caudal – peduncle length 11.5% SL (8.7 in SL). Caudal – peduncle depth 13.4% SL (7.5 in SL).

Predorsal-fin length 72.0% SL (1.4 in SL). Preanal-fin length 73.2% SL (1.4 in SL). Prepectoralfin length 40.1% SL (2.5 in SL). Predisc length 20.4% SL (4.9 in SL). Disc length 25.5% SL (3.9 in SL). Disc membrane inserting at base of 21st pectoral-fin ray. Disc with 4 rows of papillae in region A, 5 rows of papillae in region B, and 4 rows of papillae in region C ( Figure 8 ). Several rows of lateral papillae in disc region A. Caudal-fin length 17.2% SL (5.8 in SL).

Colour in life

Unknown.

Colour in alcohol

Head and body yellowish white; eyes dark grey.

Distribution

Eastern Atlantic Ocean : Canary Islands (Gran Canaria) . Probably more widespread in the region. The species was collected at 165 m depth, on hard substrate among algae.

Remarks

A record of Diplecogaster ctenocrypta (non Briggs 1955) from the Gulf of Guinea by Böhlke and Robins (1970, p. 6) is probably based on a different species.

Figures

Figure 7. Diplecogaster ctenocrypta Briggs 1955, ZMUC P9037, holotype, 15.7 mm SL, Gran Canaria. (A) Lateral view; (B) dorsal view. Bar 2 mm.

Figure 8. Diplecogaster ctenocrypta Briggs 1955, ZMUC P9037, holotype, 15.7 mm SL, Gran Canaria. Pelvic disc. Bar 1 mm.

Figure 9. Diplecogaster ctenocrypta Briggs 1955, ZMUC P9037, holotype, 15.7 mm SL, Gran Canaria. (A) dorsal view of head; (B) ventral view of head. Bar 1 mm.