Gobius salamansa, a new species of goby (Gobiidae) from the Cape Verde Islands supported by a unique cephalic lateral line system and DNA barcoding

Gobius salamansa sp. nov., a new species of tropical eastern Atlantic goby (Teleostei: Gobiidae: Gobiinae) is described from the island of So 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 alpha', part of the anterior oculoscapular canal and connected to pore alpha 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.