intermedia (Steindachner, 1877)
contributors to this species:
Daniel Blom (4) Yann
Fulliquet (2) Allan James
(3) Graham Ramsay (1)
||Dorsal spines (total):
1; Dorsal soft rays (total): 4 - 5; Anal soft rays: 9 - 10; Vertebrae:
35 - 36. Differs from other species by having a wide elliptical
cranial fontanel; short postcleithral process not reaching vertical
through origin of dorsal fin; body coloration variable, usually
with elliptical spots along sides of body, large specimens with
faint spots; or color pattern uniformly pale brown; and caudal fin
with small spots or pale brown. The only other Tatia with
a variable coloration is Tatia galaxias, but this species
differs from Tatia galaxias by its short postcleithral
process ; its small eye, 21.4-26.3% HL and its long snout 38.8-44.3%
HL. Can be further diagnosed by the following characters: nasal
ossified with wide medial flanges partially sutured to lateral margin
of mesethmoid and caudal-fin lobes of mature females with same length,
but mature males with elongated upper lobe are other distinguishing
features. Description: A iii,6-7; V i5. Post-Weberian vertebrae
35-36. The anal fin is the key to the sexual dimorphism of this
genus, if you think of the male and female of most livebearer fish
(Goodeidae family) and you wil not be too far away with this
assumption. The female has a normal anal fin but the males are modified
into a copulatory organ with the first and second ray thickened
and longer, it is thought that the male uses this to clasp the female
during the spawning embrace.
America: Amazon River basin and rivers of the Guianas.
Type locality: Marabitanos; Pará, Brazil.
||Froese, R. and
D. Pauly. Editors. 2009.FishBase. World Wide Web electronic
publication. www.fishbase.org, version (08/2009).
ScotCat Factsheet no. 048; June 2000.