Redescription of the perciform fish Symphysanodon disii (Symphysanodontidae) from the Gulf of Aqaba, Red Sea, with comments on S. pitondelafournaisei and sexual dimorphism in the genus WILLIAM D. ANDERSON, JR. (USA), AVI BARANES (Israel) & MENACHEM GOREN (Israel)

Abstract

Symphysanodon disii was described in 2008 from a single specimen collected in October 1999 from the Gulf of Aqaba. More recently, March 2008, four additional specimens of this species were collected in the Gulf. The following characters in combination distinguish S. disii from the other species in the genus: parapophyses on the first caudal vertebra, tubed scales in the lateral line 48 to 50, total number of first-arch gillrakers 34 to 37, sum of total number of gillrakers plus lateral-line scales (in individual specimens) 82 to 87, pectoral-fin rays 16 or 17, fleshy orbit diameter 7.2 to 8.3 % SL, and second anal-spine length 8.3 to 9.7 % SL. We redescribe S.disii, comment on S. pitondelafournaisei from the southwestern Indian Ocean off Reunion Island, and discuss sexual dimorphism in the genus.