Iguanodectes variatus GÉRY, 1993

Etymology

Iguanodectes: from the Taino iwana, meaning ‘lizard’, and Ancient Greek déktés, meaning ‘biter’.

variatus: from the Latin variatus, meaning ‘diversified, variegated’.

Classification

Order: Characiformes Family: Iguanodectidae

Distribution

This species has been recorded from the Guaporé, Madeira, Branco, Trombetas, and Urubu river systems within the Amazon river basin, Brazil.

Type locality is ‘Igarapé Jatuarana, 5 kilometers above Samuel, Rio Guaporé, Rondonia, Brazil’.

Maximum Standard Length

The largest specimen known to date measured 103 mm.

NotesTop ↑

Iguanodectes is a relatively small genus with less than ten member species and no additions since the early 1990s.

It is included in the family Iguanodectidae alongside the  related genus Piabucus which is separated from Iguanodectes by possession of enlarged pectoral fins and a prominent pectoral keel.

This grouping was considered to represent a subfamily, Iguanodectinae, prior to phylogenetic analyses (Moreira, 2002; Mirande, 2010) although its monophyly was evidenced much earlier based on characters of the swim bladder (Vari, 1977).

All iguanodectids possess the following characters: body elongate; teeth basally-contracted and multicuspid; gill membranes united and free from the isthmus; posterior end of maxilla not extending to eye; dorsal-fin origin normally positioned posterior to midbody (except in Iguanodectes geisleri in which it is at midbody); anal-fin long (except in I. geisleri).

In addition there is a process on the internal face of the dentary, the first proximal anal-fin pterygiophore is expanded and recurved posteriorly (except in I. geisleri), and the anterior portion of the posterior swimbladder chamber is thinner than the posterior portion (Moreira in Reis et al. 2003).

References

1. Géry, J., 1993 - Revue française d'Aquariologie Herpétologie 19(4) [for 1992]: 97-106
   Description de trois espèces nouvelles du genre Iguanodectes (Pisces, Characiformes, Characidae), avec quelques données récentes sur les autres espèces.
2. Cope, E. D., 1872 - Proceedings of the Academy of Natural Sciences of Philadelphia v. 23: 250-294, Pls. 3-16
   On the fishes of the Ambyiacu River.
3. Mirande, J. M., 2010 - Neotropical Ichthyology 9(1): 385-568
   Phylogeny of the family Characidae (Teleostei: Characiformes) from characters to taxonomy.
4. Reis, R. E., S. O. Kullander and C. J. Ferraris, Jr. (eds), 2003 - EDIPUCRS, Porto Alegre: i-xi + 1-729
   Check list of the freshwater fishes of South and Central America. CLOFFSCA.