POECILIIDAE

Sánchez, Alberto J., Álvarez-Pliego, Nicolás, Espinosa-Pérez, Héctor, Florido, Rosa, Macossay-Cortez, Alberto, Barba, Everardo, Salcedo, Miguel Ángel & Garrido-Mora, Arturo, 2019, Species richness of urban and rural fish assemblages in the Grijalva Basin floodplain, southern Gulf of Mexico, Cybium 43 (3), pp. 239-254 : 253-254

POECILIIDAE

1a. Elongated jaws with long, sharp teeth................................................. Belonesox belizanus ( Fig. 3.16 ) 1b. Short mandibles without long and sharp teeth..............2 2a. Pelvic fins in males longer than in females, reach and exceed origin of anal fin; 2 nd ray elongated.........................3 2b. Pelvic fins of same size in males and females..............5

3a. Gonopodium with hood, ray 3 can form small hook.........4 3b. Gonopodium without hood, ray 3 with strong hook................................... Xiphophorus maculatus ( Fig. 3.25 )

4a. Dorsal fin origin in advance of pelvic fin insertion, rays 12-16.................................. Poecilia kykesis ( Fig. 3.23 ) 4b. Dorsal fin origin behind pelvic fin insertion, rays 8-11...................................... Poecilia mexicana ( Fig. 3.24 )

5a. Gonopodium rays arranged in a tube.....................6 5b. Gonopodium rays not arranged in a tube..................8

6a. Elongated body; gonopodial tube on left side and 5 narrow vertical bars on sides...................... Poeciliopsis fasciata 6b. Rhomboidal body; gonopodial tube on right side...........7

7a. Gonopodium does not reach caudal fin; dorsal fin angular with edge concave with posterior black blotch in adults; scales in lateral series 26-27.................. Carlhubbsia kidderi ( Fig. 3.17 ) 7b. Gonopodium reaches caudal fin; dorsal fin rounded and edge blackened; intense lateral bars in half of body; scales in lateral series 22-24.............. Phallichthys fairweatheri ( Fig. 3.22 )

8a. Gonopodium with fleshy lateral palps........................................... Heterophallus echeagarayi ( Fig. 3.21 ) 8b. Gonopodium without fleshy lateral palps.................9

9a. Without hooks at distal end of gonopodial rays 4 and 5; dorsal rays 11-17; blotch on caudal peduncle......................................... Pseudoxiphophorus bimaculatus ( Fig. 3.20 ) 9b. With hooks at distal end of gonopodial rays 4 and 5; dorsal rays 6-9; with suborbital blotch and dark spots on body............10

10a. Body sides with spots arranged in lines; dorsal rays 6-8; obtuse gonopodial apex............. Gambusia sexradiata ( Fig. 3.18 ) 10b. Body sides with spots arranged irregularly; dorsal rays 7-9; acute gonopodial apex.......... Gambusia yucatana ( Fig. 3.19 )

Figures

Figure 3. – Fish distributed in the Villahermosa city and rural areas in the Grijalva floodplain. 1 – Anchoa mitchilli, 2 – Brevoortia gunteri, 3 – Hyphessobrycon compressus, 4 – Batrachoides goldmani, 5 – Dormitator maculatus, 6 – Eleotris amblyopsis, 7 – Gobiomorus dormi- tor, 8 – Oreochromis aureus, 9 – Rocio octofasciata, 10 – Thorichthys helleri, 11 – T. meeki, 12 – T. pasionis, 13 – Trichromis salvini, 14 – Atherinella alvarezi, 15 – Cynodonichthys tenuis, 16 – Belonesox belizanus, 17 – Carlhubbsia kidderi, 18 – Gambusia sexradiata, 19 – G. yucatana, 20 – Pseudoxiphophorus bimaculatus, 21 – Heterophallus echeagarayi, 22 – Phallichthys fairweatheri, 23 – Poecilia kykesis, 24 – P. mexicana. 25 – Xiphophorus maculatus, 26 – Achirus lineatus, and 27 – Microphis lineatus.