Llanolebias, Hrbek, Tomas & Taphorn, Donald C., 2008

Hrbek, Tomas & Taphorn, Donald C., 2008, Description of a new annual rivulid killifish genus from Venezuela, Zootaxa 1734, pp. 27-42 : 36-38

Llanolebias new genus

Fig. 4 (male and female), Fig. 5 (male and female MCNG 25828)

Type species. Rivulus stellifer Thomerson & Turner 1973 . Holotype: USNM 209254; Paratypes: USNM 209254, FMNH 71667, FMNH 71668, UMMZ 193375, CAS 27556, MBUCV V- 7199, ICNMHN 700.

Diagnosis. Llanolebias is diagnosed by the numerous molecular characters, however, it possesses no unique morphological characters that will unambiguously distinguish it from all other rivulid species; however, 13 characters distinguishing it from the genus Rachovia , and 33 characters distinguish it from the genus Gnatholebias . Compared to its sister genus Gnatholebias , the single species of Llanolebias is a robust, cylindrical-shaped fish, with short fins and in males very small fin-ray extensions, while Gnatholebias species have relatively deep, laterally compressed bodies with long fins and long fin-ray extensions. The anal fin base of Llanolebias is also short compared to species of Gnatholebias , and Llanolebias has 14-15 anal fin rays versus 22-26 fin rays in Gnatholebias . Llanolebias also lacks the fatty predorsal ridge characteristic of older males of Rachovia . With the sole exception of females of Renova oscari Thomerson & Taphorn, 1995 , Llanolebias is the only member of the ‘lowland annual’ clade of Rivulidae ( Hrbek & Larson, 1999) with a ‘Rivulus’ spot in females. Llanolebias stellifer also differs ecologically from the two species of Gnatholebias . Llanolebias stellifer occurs in shallow habitats on the edges of aquatic systems in deep forest, whilst Gnatholebias zonatus is from sunny pools in the savannah and Gnatholebias hoignei (Thomerson, 1974) is from shaded but deeper pools than L. stellifer . Llanolebias stellifer is confined to seasonally wet areas in the seasonally dry tropical forest region of the Llanos, and is found in a habitat similar to that occupied by species of the genera Aphyolebias and Moema which are found in seasonally wet areas of dense tropical forests of the Amazon and Essequibo basin.

Included taxa. Only the type species.

Etymology. From the Spanish Llanos (grassy plains, and in particular the Orinoco River savannahs of Venezuela and Colombia) and the Greek Lebia (a small fish and a nominal cyprinodontiform genus). Gender masculine.

Figures

FIGURE 5. An adult male (5 a) and female (5 b) Llanolebias stellifer deposited in the MCNG collection (MCNG 25828).

FIGURE 4. A representative female (4 a) and male (4 b) Llanolebias stellifer (photos by Tonnie Woeltjes).