Pterolebias phasianus

biology_ecology

Habitat notes: Temporary lagoons in the Pantanal. Often sympatric with P. longipinnis, in which cases P. phasianus is usually found in shaded areas and P. longipinnis is found in sunny areas.

The Neotropical annual killifish genus Pterolebias Garman (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology, and taxonomic revision.

description

Description. Morphometric data appear in Table 2. Males larger than females, largest male 41.8 mm SL. Dorsal profile slightly convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile slightly convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Body slender, subcylindrical anteriorly, slightly deeper than wide, to compressed posteriorly. Greatest body depth at level of pelvic-fin base. Jaws short, snout slightly pointed. Tip of dorsal fin pointed with short filamentous rays in males, rounded to slightly pointed in females. Anal fin approximately rectangular, longer than deep; tip pointed with filamentous rays, long, reaching vertical through middle of caudal fin in males, rounded and short in females. Caudal fin elliptical, long; filamentous rays on posterior edge of male caudal fin. Pectoral fin elliptical, posterior margin reaching vertical just posterior to pelvic-fin base. Pelvic fin long, its tip reaching between middle of anal-fin base and caudal-fin base in males, and between urogenital papilla and base of 2 nd anal-fin ray in females. Dorsal-fin origin on vertical between base of 11 th and 12 th an

The Neotropical annual killifish genus Pterolebias Garman (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology, and taxonomic revision.

diagnosis

Diagnosis: Readily distinguished from P. longipinnis by having slender body (body depth 19.5 - 23.0 % SL vs. 25.0 - 28.8 % SL in males, 19.4 - 23.1 % SL vs. 25.3 - 27.0 % SL in females; caudal peduncle depth 11.8 - 14.8 % SL vs. 15.8 - 17.8 % SL in males, 11.9 - 13.7 % SL vs. 14.9 - 16.8 % SL in females), a single row of scales on the anal-fin base in males (vs. three to seven rows), no scales on the dorsal-fin base in males (vs. one or two rows of scales), pelvic-fin bases separated (vs. medially united), fewer neuromasts in the infraorbital series (1 - 2 + 16 - 17 + 1, vs. 2 - 3 + 19 - 21 + 1), preopercular series (2 + 9 - 10, vs. 2 + 11 - 14), and mandibular series (5 + 2, vs. 6 - 7 + 2 - 4), flank blue with dark brown stripes (vs. light brown with oblique rows of green dots), and presence of a subdistal zigzag bluish white line on anal fin in males (vs. absence). Pterolebias phasianus usually has fewer dorsal and anal fin rays than P. longipinnis (7 - 9 and 15 - 17, respectively, vs. 9 - 11 and 17 - 22).

The Neotropical annual killifish genus Pterolebias Garman (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology, and taxonomic revision.

distribution

Distribution: Middle Paraguay River basin, in Brazil and Bolivia (Fig. 8).

The Neotropical annual killifish genus Pterolebias Garman (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology, and taxonomic revision.