The filamentous flounder Arnoglossus nigrofilamentosus n. sp. is described from four specimens collected in the southeastern Mediterranean near Tel-Aviv, Israel on 5 May 2017. The new species is characterized as follows: second to sixth dorsal-fin rays elongate and filamentous, dorsal-fin rays 78-84, anal-fin rays 61-66, pectoral-fin rays on ocular side 12-13, on blind side 7-9, caudal-fin rays iii,11,iii , lateral-line scales 52-54, gill rakers 0 + 4-5, not serrated, interorbital a narrow bony ridge without scales in the middle, interorbital width 11% to 16% of upper orbit diameter, no enlarged teeth anteriorly in upper jaw, and prevomer small, not enlarged, weakly projecting into mouth cavity; body in fresh specimens pale (may have been dark before the epidermis was abrased), head, peritoneum and vertical fins black. The new species is described and compared with similar species. Though the species has not yet been observed in the northern Red Sea, it probably originates from the Gulf of Suez, so this finding represents a probable new case of Lessepsian migration. |