Atherinopsidae

Malabarba, Luiz R. & Dyer, Brian S., 2002, Description of three new species of the genus Odontesthes from the rio Tramandaí drainage, Brazil (Atheriniformes: Atherinopsidae), Ichthyol. Explor. Freshwaters 13, No. 3, pp. 257-272 : 259-260

Key of Atherinopsidae species from rio Tramandaf drainage (specimens larger than 140 mm SL)

1. -Rostralsensorysystem bearing 4 anterior and 2posterior fossae; 35-40 scales in lateral lineseries abovelateral band. ... Atherine ll a(Xenom elaniris)brasiliensis

-Rostral sensorysystem absent;48-60 scales inlateral lineseries above lateral band. ....................................................... 2

2. - 9- 11 longitudinal rows of scales between seconddorsalandanalfins;53-60 scales in laterallineseriesabovelateral band; 29-35 predorsalscale rows; 18-20 scale rows aroundcaudalpeduncle; 9-10 longitudinal scalerowsbetween left and right lateral bandsabovepelvic fins; 30-38 lower gill rakers;40-48totalgillraker count. ...................................Odontesthes bonariensis

- 8longitudinalrows ofscales between seconddorsalandanalfins; 48-52 scales in the lateral line seriesabovethelateral band (47­ 53 in O.piquava ); 23-26 predorsal scale rows; 13-16scalerowsaround caudal peduncle; 6 -7longitudinalscalerowsbetween left and rightlateralbandsabove pelvic fins; 26-30 lowergill rakers;32-37total gill raker count. ....................................... 3

3. - Three longitudinal series of scales in the infraorbital area; anterior row of teeth longer and more robust than posterior row of teeth. ............................. Odontesthes argentinensis

- Two longitudinal series of scales in the infraorbital area; anterior row of teeth shorter than posterior row of teeth ( Odontesthes perugiae species-group). ........................... 4

4 -Ventralheadprofileusually split into two straight sections,forming an angle at retroarticularjoint; mouthslightly upturned in lateralview,andpositioned above an horizontallinecrossing nearcenter of eye and above anhorizontallinecrossing near middle ofheaddepth( Fig.2b);premaxilla not extendedanteriorlyinits medialmost portion; snout short,aslong as wide in dorsal view( Fig.2c). ....................................... Odontesthes piquava

-Ventralheadprofilenearlystraight,or with slightconvexityatretroarticularjoint;mouth terminal,positioned in an horizontal line crossingnearcenterofeyes pupil and middle ofheaddepth( Figs. 3b , 4b);premaxilla extendedanteriorlyinits medialmost por - tion; snoutelongated, pointedin dorsal view ( Figs.3 c ,4c). ...................... 5

5. -Widthofanteriorexposed dorsal border of thepremaxilla2- 4times wider than exposedportionofposterolateral branches of premaxilla( Fig.3c );snout length clearly largerthan interorbital width (snout length 1.2 -1.7 times interorbital width,mean = 1.4, n = 35);eyessmall, diameter 1.4-2.2 times snoutlength(mean =1.7,n= 59). .......................................... Odontesthes bicudo

- Widthofanteriorexposed dorsal border of thepremaxillanearlytwotimes wider than theexposedportion of the posterolateral branchesofthepremaxilla ( Fig. 4c ); snout lengthnearlyequalorlarger than interor - bitalwidth(snout length 0.9-1.3 times inter - orbitalwidth, mean = 1.1, n = 22);eye diameter 1.1 -1.6timessnoutlength (mean = 1.4, n = 56). .................................... ........ Odontesthes ledae

Figures

Fig. 3. Odontesthes bicudo, holotype, MCP 26153, 158 mm SL; Brazil, lagoa Emboaba. a, left view; b, head, left view; c, head, dorsal view

Fig. 4. OdontesHies ledae, holotype, MCP 26151, 136.6 mm SL; Brazil, lagoa Fortaleza, a, left view; b, head, left view, c, head, dorsal view