Gobius couchi Miller & El-Tawil, 1974

Kovačić, Marcelo, Bonello, Juan Jose & Evans, Julian, 2013, Three new records of Gobiidae from Malta with morphology, colouration and identification of the smallest known juveniles of two small gobiid species, Cybium 37 (4), pp. 233-239 : 234-235

Gobius couchi Miller & El-Tawil, 1974

Material examined

Juvenile of unidentified sex, PMR VP2884 ( Fig. 2A ), 18.2 + 4.2 mm, Tigné (H5), Malta, 29 Aug. 2011, coll. J.J. Bonello and J. Evans ( Figs 1 , 2B ) .

Diagnosis

(1) Suborbital papillae of lateral-line system without longitudinal row a; (2) all three head canals present; (3) scales present on predorsal area; (4) anterior oculoscapular canal with pore α at rear of orbit; (5) scales in lateral series on both sides 39 (known species range of scales in lateral series is 35-45, Miller, 1986); (6) pectoral fin 16 (known species range of pectoral fin rays 15-18, Miller, 1986); (7) row d divided below row 3; (8) pelvic fin truncate (known species with rounded to truncated pelvic fins, Miller, 1986).

Description

Anterior nostril short, tubular, with higher posterior rim. Branchiostegal membrane attached to entire side of isthmus. First dorsal fin VI, second dorsal fin I/13, anal fin I/12, caudal fin with 14 branched rays and 16 segmented rays, pectoral fin 16, pelvic fins I/5+5/I. Free tips on pectoral fin rays not visible. Pelvic fin truncate. Anterior membrane height in midline 1/3 length of pelvic fin’s spinous ray. Body with ctenoid scales, scales in lateral series 39. Opercle and cheek naked, scales present on predorsal area. Preserved colour: body light brown with reticulate pattern, formed by pigmentation along the margins of most scales. Breast and belly pale. Most distinct marks were about nine darker blotches along lateral midline. Head similar to body, with two dark spots on cheek and dark-pigmented snout. Three longitudinally arranged dark gular spots with fourth dark spot on ventral part of opercle. Dorsal and caudal fins with rows of small dark dots. Anal fin and the bases of anal fin rays pigmented. Pectoral fin with dark mark in upper fin origin, mark deeper than long, another dark mark nearby on upper pectoral base. Pelvic fins pale. Head with anterior and posterior oculoscapular, and preopercular canals, with pores σ, λ, Χ, ω, α, β, ρ, ρ 1, ρ 2, and γ, δ, ε, respectively. Rows of suborbital papillae of lateral-line system without longitudinal row a; six transverse suborbital rows of sensory papillae. Longitudinal suborbital row d divided below suborbital row 3. Oculoscapular anterior longitudinal row x 1 ending anteriorly behind pore β.

Figures

Figure 1. - Map of the Maltese Islands showing the sixteen sampling locations: (▲) sites with gobiid records; (●) sites from where no gobiid species were identified. Key: A: Wied l-Ghasri; B: Ħondoq Bay; C: Ix-Xatt l-Ahmar; D: Mġarr ix-Xini; E: Mellieha Bay; F: Mistra Bay; G: Qawra; H1-H6: Tigné A – Tigné F; I1-I2: Manoel Island A – Manoel Island B; J1-J4: Ta’ Xbiex A – Ta’ Xbiex D; K: Ħofra ż-Żghira; L: Marsaxlokk; M: Wied ix-Xoqqa; N: Wied iż-Żurrieq; O: Fomm ir-Rih Bay; P: Ġnejna Bay.

Figure 2. - Gobius couchi. A: Preserved specimen, PMR VP2884, juvenile of unidentified sex, 18.2 + 4.2 mm, Tigné E, Malta. B: Map of the Mediterranean showing previous records (▲) and new find- ing (●).