217 



Ageneiosus piperatus (Eigenmann), new combination 



Fig. 40 

 Table 10 



Tympanopleura piperata Eigenmann 1912:203-204; pi. 10, fig. 3 (original description 

 [type locality: Essequibo River at Crab Falls, British Guiana { = Guyana}]). 

 Henn 1928:75 (holotype listed). Eigenmann and Myers, in Myers 1928:85 

 (comments on size and comparison with T. alta). Eigenmann and Allen 

 1942:138 (designated type species of genus). Gosline 1945:25 (citation). 

 Fowler 1951:456 (cited as generic type [orthotype]). Ibarra and Stewart 

 1987:84,86 (holotype and paratype listed). Burgess 1989:286 (citation). 



Ageneiosus piperatus: Britski 1972:104, 109 (cited as generic type [orthotype]; new 

 combination). Ferraris 1988:122, 125, 128 (citation; nomenclatural status of 

 Tympanopleura). 



Diagnosis 



Known at present from very few specimens. A diminutive ageneiosid, 

 reaching sexual maturity at less than 50 mm SL. Further distinguished from all 

 other ageneiosids by a combination of its low numbers of ribs (5), pectoral rays 

 (1+9), and branchiostegals (7-8). Posterior processes of epioccipital pronounced, 

 reaching laterally to skin midway between dorsal and pectoral fins. Swimbladder 

 large in adults, lying just beneath posterior epioccipital processes and extending 

 laterally to skin; integument in area of contact with swimbladder bulging slightly 

 outward, forming semi-translucent, ovoid or triangular membranous patch covered 

 partially by dense concentration of chromatophores. Snout very short, eye large, 

 gape small and not greatly recurved in ventral profile. Body profusely speckled with 

 minute melanophores, condensed into a dark patch on the chin and an hourglass- 

 shaped band across the base of the caudal fin. 



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