Silhouettea, in Miller, 1988

Kovačić, Marcelo, Sadeghi, Reza & Esmaeili, Hamid Reza, 2020, New species of Silhouettea (Teleostei: Gobiidae) from Qeshm Island, Iran and the DNA barcoding of the Persian Gulf and Oman Sea gobies, Zootaxa 4750 (1), pp. 49-66 : 55

Key to valid species of Silhouettea

(modified from Miller (1988) to accommodate S. capitlineata and the new species)

1a First dorsal fin spines II–IV, not extending rearwards beyond anterior end of the second dorsal fin when depressed; body with lateral midline blotches more or less evident; estuarine or marine............................................... 2

1b First dorsal fin spines II–IV, extending rearwards beyond middle of the second dorsal fin when depressed; body with four narrow vertical dark striae; freshwater, Lake Sibaya, Mozambique........................................... S. sibayi

2a Head length 31.4–35.5% of standard length, head width 20.5–24.6% of standard length.............................. 3

2b Head length 20.1–30.0% of standard length, head width 11.6–15.5% of standard length.............................. 4

3a Anal fin I/12, opercle and predorsal area with scales, Marshall Islands, Pacific Ocean..................... S. capitlineata

3b Anal fin I/13, opercle and predorsal area naked, Qeshm Island, Indian Ocean............... Silhouettea ghazalae sp. nov.

4a Lateral midline with 9-10 short vertical dark marks, each within oblong or rhomboidal dark blotch; body scale pocket beneath scale with numerous fine melanophores in crescentic dark mark, the Northern Red Sea, introduced to Mediterranean.................................................................................................. S. aegyptia

4b Lateral midline with at least four to six oblong to triangular blotches more or less evident but lacking distinct vertical central mark (up to ten in S. dotui ); body scale pocket with crescentic mark beneath scale formed by fewer larger melanophores... 5

5a Anal fin I/13–14...................................................................................... 6

5b Anal fin I/11–12...................................................................................... 7

6a Nape lacking conspicuous white spot; the first dorsal fin with anterior dark spot but no obvious posterior spot; pectoral fin 14–15; Indian Ocean and Red Sea............................................................... S. insinuans

6b Nape with conspicuous white spot; the first dorsal fin with posterior dark spot but no obvious anterior spot; pectoral fin 16; Philippines............................................................................. S. nuchipunctatus

7a Anal fin I/12; Japan and India........................................................................... 8

7b Anal fin I/11; northern Australia......................................................................... 9

8a Body densely pigmented with coarse reticulation of numerous crescentic scale pocket marks; up to ten small not very evident lateral midline markings small, median fins less than body height; breast scaled; Japan......................... S. dotui

8b Body with six oval blotches along lateral midline; median fins higher than body, breast naked; India............. S. indica

9a Axilla pigmented; lateral blotches small; nape with transverse band of fine melanophores narrower than pupil; branchiostegal membrane pale................................................................................ S. evanida

9b Axilla pale, lateral blotches large; nape with transverse band of fine melanophores wider than pupil; branchiostegal membrane densely pigmented.............................................................................. S. hoesei