Bothidae, Smitt, 1892

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 156-157

Key to genera of Bothidae in Taiwan

1A. First pelvic-fin ray on blind side opposite to second ray on ocular side; origin of pelvic fin on ocular side slightly behind tip of isthmus, their distance subequal to base length of pelvic fin on ocular side; lower part of urohyal truncate distally........................................................................................... Taeniopsetta (1 species)

1B. First pelvic-fin ray on blind side opposite to third or fourth ray on ocular side; origin of pelvic fin on ocular side at or near tip of isthmus; lower part of urohyal pointed distally............................................................ 2

2A. Mouth extremely large, maxillary length more than half of HL; end of upper jaw extend to or well behind posterior margin of eye................................................................................................. 3

2B. Mouth small to moderate large, maxillary length less than half of HL; end of upper jaw before posterior margin of eye..... 4

3A. Anterior tip of upper jaw extending beyond snout tip; pectoral-fin length on ocular side longer than HL..... Kamoharaia (1)

3B. Anterior tip of upper jaw not extending beyond snout tip; pectoral-fin length on ocular side shorter than HL.................................................................................................. Chascanopsetta (2)

4A. Eyes separated by a broad concave space; interorbital space wider in males than in females and in large specimens than small ones of same sex; rostral spine usually present in males....................................................... 5

4B. Eyes separated by a bony ridge or distinctly narrow anteriorly, no sexual dimorphism on interorbital space; no rostral spine.. .................................................................................................. 11

5A. First dorsal-fin ray elongate, lure-like, longer than and free from the second ray; gill rakers palmate...... Asterorhombus (2)

5B. First dorsal-fin ray shorter than second, connected to each other by fin membrane; gill rakers not palmate in shape........ 6

6A. Tip of isthmus below posterior margin of eye............................................................... 7

6B. Tip of isthmus below middle to anterior margin of eye........................................................ 8

7A. Body long elliptical, body depth <46.2% SL................................................... Parabothus (4)

7B. Body ovoid, body depth> 50% SL.......................................................... Tosarhombus (1)

8A. LLs> 76............................................................................................ 9

8B. LLs <61........................................................................................... 10

9A. Anterior dorsal-fin rays elongate; 3 clear ocelli on body....................................... Grammatobothus (2)

9B. Anterior dorsal-fin rays not elongate; no clear ocelli on body............................................ Bothus (3)

10A. Scales ctenoid, with long hair like spines on posterior margin; body dark brown, with a large dark blue blotch on blind side in males................................................................................. Crossorhombus (4)

10B. Scales ctenoid, with short spines on posterior margin; body greyish or greenish brown, light grayish on blind side in males........................................................................................ Engyprosopon (9)

11A. HL> 22% SL; vert. <45.............................................................................. 12

11B. HL <21% SL; vert.> 49.............................................................................. 13

12A. Upper-jaw length about equal to eye diameter; scales with long hair like spines on posterior margin............ Psettina (4)

12B. Upper-jaw length longer than eye diameter; scales cycloids or ctenoids with short spines on posterior margin.................................................................................................... Arnoglossus (6)

13A. Upper-jaw length 3.1–6.2% SL, lower-jaw length 5.6–7.8%, upper-eye diameter 4.8–6.2%; vert. 11–12+37–42=48–54.... 14

13B. Upper-jaw length 7.5–8.8% SL, lower-jaw length 10.2–11.5, upper-eye diameter 3.3–4.5; vert. 13+37–38=50–51................................................................................................... Neolaeops (1)

14A. Teeth present on both jaws of ocular side; upper-jaw length about equal to eye diameter; HL 18.1–20.6% SL.................................................................................................... Japonolaeops (1)

14B. Teeth absent on both jaws of ocular side; upper-jaw length much shorter than eye diameter; HL 14.9–17.6% SL...................................................................................................... Laeops (1)