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| Gobius salamansa |
Abstract
Gobius salamansa sp. nov., a new species of tropical eastern Atlantic goby (Teleostei: Gobiidae: Gobiinae) is described from the island of São Vicente in the Republic of Cabo Verde. With adults measuring less than 35 mm TL (total length) it is the smallest species among Gobius. It is easily distinguishable from its Atlantico-Mediterranean congeners thanks to a unique character: an additional posterior ocular head pore, newly named α’, part of the anterior oculoscapular canal and connected to pore α by a suborbital branch. The new species also possesses a rare character among gobiids: a continuous oculoscapular canal, undivided into anterior and posterior parts. The species is distinguishable from its relatives thanks to its distinctive multi-colored (white, red, black, yellow and brown) eyespot, located on the first dorsal fin; by a low number of soft rays on the second dorsal fin (11) and anal fin (9); by row r not divided into two sections; by a divided row d. The two type of specimens were collected at 0.2–0.6 m depth, at the entrance of cracks in compact volcanic boulders forming a rocky islet submerged at high tide. DNA barcoding based on COI of the species compared with sympatric gobiids and species of Atlantico-Mediterranean Gobius reveals a high nucleotide sequence divergence [Kimura’s (1980) two parameter distances of 16.5 %)], with Gobius ateriformis identified as its closest species. A dichotomous key for Gobius–Mauligobius from tropical eastern Atlantic is provided. It is the eleventh gobiid species, and the fourth endemic species, to be described in Cape Verde.
Keywords: Gobiinae, New species, Eastern Atlantic, Republic of Cabo Verde, Head pore
Diagnosis. The new species is characterized by a unique character among the gobiids: (1) an additional posterior ocular head pore, newly named α’, and connected to pore α by a suborbital branch of the anterior oculoscapular canal; (2) a distinctive multi-colored (white, red, black, yellow and brown) eyespot, located on the first dorsal fin. The new species is also characterised by the combination of the following characters: (1) the possession of pores on the oculoscapular (σ, λ, κ, ω, α, β, ρ, ρ1, ρ2), and preopercular (γ, δ, ε) head canals; (2) a canal section between pore ρ and ρ1 connecting the anterior and the posterior oculoscapular canals; (3) a divided row d; (4) row r not being split into two sections; (5) row x1 ending anteriorly behind pore β; (6) six transverse infraorbital rows of sensory papillae (1–6), with five anterior to the hyomandibular row b but only one above, and with the inferior sections of rows five and six well developed below row b; (7) row g ending behind row o; (8) six well developed upper free pectoral rays; (9) anterior nostril with a digitate process; (10) predorsal area and nape scaled; (11) 11 soft rays on the second dorsal, 9 soft rays on the anal fin; (12) 36–37 scales on LL; (13) a scaleless cheek and opercle. The new species also differs from close Gobius–Mauligobius relatives by the combination of the following characters: a white breast; a thin caudal peduncle, with a depth 45–50 % of caudal peduncle length; a long pectoral fin, 29–30 % of standard length; a long pelvic fin, 23–25 % of standard length; large eyes, 38–39 % of head length; a short snout, 25–26 % of head length, short interorbital width, 7.5–8.5 % of eye diameter.
Distribution and habitat. — Known presently only in the Bay of Salamansa at São Vicente, Cape Verde Islands, 16.909545° N, -24.938012° W. The specimens were observed in a subtidal area at the entrance of cracks in compact volcanic boulders forming a rocky islet submerged at high tide about one hundred meters from the beach. The basaltic rocks were covered with short seaweeds and coralline algae. The habitat was largely colonized by the subtidal blenniids Ophioblennius atlanticus (Valenciennes in Cuvier and Valenciennes 1836) and Scartella caboverdiana Bath 1990. The rocky islet was surrounded by sand, rock and coral bottom, 1–3 m depth, where individuals of G. ateriformis were common under rocks. The sea temperature was 24 C at the point of collection.
Etymology.— The epithet salamansa refers to the village of Salamansa, on the north of the island of São Vicente, Republic of Cabo Verde , which marks the location where the only two known specimens were collected. The specific name salamansa is proposed as a noun in apposition.
Samuel P. Iglésias, Lou Frotté and Daniel Y. Sellos. 2016. Gobius salamansa, A New Species of Goby (Gobiidae) from the Cape Verde Islands supported by A Unique Cephalic Lateral Line System and DNA Barcoding. Ichthyological Research. 63(3); 356–369. DOI: 10.1007/s10228-015-0505-4
