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Matilebias periodicus (Costa, 1999) |
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photo by
Volcan, M.V. |
| Family: | Rivulidae (Rivulines), subfamily: Cynolebiinae | |||
| Max. size: | 5 cm TL (male/unsexed) | |||
| Environment: | benthopelagic; freshwater, non-migratory | |||
| Distribution: | South America: Ibicuí and Quaraí (= Cuareim) river drainages, rio Uruguay basin in southern Brazil and northwestern Uruguay. | |||
| Diagnosis: | Dorsal soft rays (total): 16-26; Anal soft rays: 17-25; Vertebrae: 27-29. Can be diagnosed from other species of the Austrolebias alexandri group by the following combination of characters: posterior margin of each pectoral fin in male reaching a vertical between base of second and fifth anal-fin rays (vs. between urogenital papilla and base of second anal-fin ray); origin of dorsal fin either on vertical through anal-fin origin or posterior to it (vs. anterior); and presence of vertical rows of light blue dots on entire flank in larger males (vs. light blue bars) (Ref. 57613). Description: Dorsal-fin rays 22- 26 in males, 16-18 in females; anal-fin rays 21-25 in males, 17-23 in females. Longitudinal series of scales 26-28; and transverse series of scales 10-12; (Ref. 57613). | |||
| Biology: | ||||
| IUCN Red List Status: | Vulnerable (VU); Date assessed: 11 December 2020 (B1ab(iii)) Ref. (130435) | |||
| Threat to humans: | harmless | |||