Redescription of Gerres longirostris (Lacepède, 1801) and Gerres oblongus Cuvier in Cuvier and Valenciennes, 1830, Included in the Gerres longirostris Complex (Perciformes: Gerreidae)

The taxonomic status of Gerres longirostris (Lacepède, 1801), Gerres britannus (Lacepède, 1802), and Gerres poieti Cuvier, 1829, is examined. Gerres longirostris is considered a valid species and a senior synonym of G. britannus, G. poieti, and Gerres acinaces Bleeker, 1854a, and four other species (Gerres lineolatus Playfair, 1867, Gerres longicaudus Alleyne and Macleay, 1876, Gerres rueppellii Klunzinger, 1884, and Gerres darnleyense Ogilby, 1913). Gerres longirostris is redescribed, with designation of a neotype from Madagascar, Indian Ocean. Gerres oblongus Cuvier, 1830, is also confirmed as a valid species and a senior synonym of Gerres macrosoma Bleeker, 1854b, and Gerres gigas Günther, 1862. A lectotype is designated for G. oblongus and a neotype for G. macrosoma. Gerres longirostris and G. oblongus belong to the ”Gerres longirostris complex.” Gerres longirostris differs from G. oblongus in having a deeper body (mean 39% SL vs mean 33% SL in G. oblongus), fewer pored lateral line scales (43–46 vs 45–49), and a broad dark caudal fin posterior margin. Both species are widely distributed in the Indo-Pacific region.

Fig. 1.

(A) Original illustration (plate 19, figure 1) of Labrus longirostris Lacepède, 1801 and (B) “Ican-Poeti” after Renard (1719:pl, 2, fig. 9) of Gerres poieti Cuvier, 1829, (C) holotype (RMNH 6686, 212 mm SL) of Gerres acinaces Bleeker, 1854, and (D) invalid “neotype [MNHN 9467, 150 mm SL, Mahé, southwestern India, proposed by Bauchot and Desoutter (1989)] of Gerres poiet Cuvier, 1829

Fig. 2.

(A) Neotype of Gerres longirostris, MNHN 1965–388, 94 mm SL; (B) lectotype of Gerres oblongus, MNHN 9497, 118 mm SL; and (C) neotype of Gerres macrosoma, RMNH 6683, 125 mm SL

Fig. 4.

Relationships of (A) body depth, (B) orbit diameter, and (C) third anal fin spine length to standard length between Gerres longirostris and Gerres oblongus

Fig. 3.

Life stages of Gerres longirostris (A–C) and Gerres oblongus (D–F). Each pair (across) comprises specimens of apporoximately equal length. (A) OMNH-P 5451, 98 mm SL, Iriomote Island, Ryukyu Islands, Japan; (B) MUFS 10399, 185 mm SL, Ryukyu Islands, Japan; (C) FRLM 13582, 259 mm SL, Ryukyu Islands, Japan; (D) MUFS 10527, 99.5 mm SL, South Africa; (E) MUFS 10574, 191 mm SL, Okinawa Island, Ryukyu Islands, Japan; (F) MUFS 10229, 140 mm SL, Iriomote Island, Ryukyu Islands, Japan

Received: 20 Sept 2000

Accepted: 18 May 2001