Comprehensive DescriptionRead full entry
Holotype : AMNH 12616 , Brazil , Rio Jurua drainage, Rio Embira .
Lamontichthys ZBK is distributed in the northwestern part of South America in the upper Amazon and Orinoco River drainages, and in the Lake Maracaibo region. Species in this genus occupy the same ecological niche as those of Harttia ZBK . They mainly live in the mainstream of rivers, on rocky and sandy bottoms (Taphorn & Lilyestrom 1984). Sexual dimorphism includes hypertrophied odontodes on the pectoral spines in mature males. Lamontichthys ZBK is an open brooder. Eggs are laid on an open surface such as rocks, submerged wood or plants, and are generally exposed to the current. Females lay a few large-sized (1.4 to 1.8 mm in diameter) yellowish eggs during each spawning event (Taphorn & Lilyestrom 1984). These authors expressed doubts concerning the value of the character given by Isbrücker & Nijssen (1978) to diagnose Lamontichthys ZBK (i. e. the number of pectoral fin rays i -7 versus i -6 for all other Loricariinae ). However, this feature is present in all species assigned to this genus, suggesting a common origin. Isbrücker & Nijssen (1976a) demonstrated that fin ray numbers, with few exceptions, were particularly conservative among members of Loricariinae . The phylogenetic position of Lamontichthys ZBK remains uncertain. Rapp Py-Daniel (1997) considers it to be sister to Harttia ZBK , whereas Lamontichthys ZBK shows much more similarities with Pterosturisoma ZBK , a monotypic genus which only differs from Lamontichthys ZBK by the number of pectoral fin rays. Nevertheless, Rapp Py-Daniel (1997) tentavely placed Pterosturisoma ZBK within Harttiina because of its similarity with Lamontichthys ZBK , but did not provide any hypotheses on the phylogenetic relationships between these genera. Lamontichthys ZBK includes four valid species, and a key to their identification is available in Taphorn & Lilyestrom (1984).