Artigo

A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes

We studied a specialised assemblage of sand-dwelling fish species from a streamlet in central Amazonia. The five sand-dwelling species comprised 15.2 % of the total number in the streamlet (33 species). Two of the sand-dwellers are daytime foragers, Characidium cf. pteroides (Crenuchidae) and Stauro...

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Autor principal: Zuanon, Jansen
Outros Autores: Bockmann, Flávio Alicino, Sazima, Ivan
Grau: Artigo
Idioma: English
Publicado em: Neotropical Ichthyology 2020
Assuntos:
Barbus
Characidium
Crenuchidae
Gymnorhamphichthys
Heptapteridae
Imparfinis
Pisces
Rhamphichthyidae
Trichomycteridae
Acesso em linha: https://repositorio.inpa.gov.br/handle/1/14636
id oai:repositorio:1-14636
recordtype dspace
spelling oai:repositorio:1-14636 A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes Zuanon, Jansen Bockmann, Flávio Alicino Sazima, Ivan Barbus Characidium Crenuchidae Gymnorhamphichthys Heptapteridae Imparfinis Pisces Rhamphichthyidae Trichomycteridae We studied a specialised assemblage of sand-dwelling fish species from a streamlet in central Amazonia. The five sand-dwelling species comprised 15.2 % of the total number in the streamlet (33 species). Two of the sand-dwellers are daytime foragers, Characidium cf. pteroides (Crenuchidae) and Stauroglanis gouldingi (Trichomycteridae), whereas three ones are night-time foragers, Gymnorhamphichthys rondoni (Rhamphichthyidae), "Imparfinis" pristos and Mastiglanis asopos (Heptapteridae). With the exception of C. cf. pteroides, the remainder species bury in the sand during their resting period. All five species bear a cryptic, sand-colour pattern, and some are translucent, traits which we regard as advantageous both for evasion from predators and for approaching prey (for the daytime foragers). All five species are microphagous carnivores and their foraging tactics range from generalised sit-and-wait (C. cf. pteroides) to active searching for interstitial prey (G. rondoni). A unique "drift-trap" system made up by the extended barbels and filamentous first pectoral-fin rays is employed by M. asopos. We regard the small size and low number of vertebrae (which is functionally expressed by fast displacements in the sand) as additional features advantageous to explore the sand habitat, allowing diving quickly in the substrate to evade predators and to forage for small prey in sand interstices or plant debris. The relationship between morphological and behavioural characters suited to life in sandy substrates is examined under the perspective of the current phylogenies for each group of psammophilous fishes here studied. The mapping of these characters demonstrates that not all of them evolved specifically for strict psammophily. Instead, some of them may represent the final step of a transformation series or synapomorphies of higher hierarchical levels. Several characters linked to psammophily, such as small body, large eyes, and scarce pigmentation are probably paedomorphic traits. We consider that the little variable specific composition of fish sand-dwelling assemblages and the wide (although patchy) geographical distribution of their species in the Amazon are due to the widespread occurrence and low complexity of this specialised habitat. The pre-existence of benthic habits, small size, and the broad distribution of rivers with sandy beds, mainly in the Amazon and Orinoco basins, possibly played a determinant role in the origin and diversification of psammophilous assemblages among freshwater fishes in South America. Copyright © 2006 Sociedade Brasileira de Ictiologia. 2020-04-24T16:55:33Z 2020-04-24T16:55:33Z 2006 Artigo https://repositorio.inpa.gov.br/handle/1/14636 10.1590/S1679-62252006000100012 en Volume 4, Número 1, Pags. 107-118 Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ application/pdf Neotropical Ichthyology
institution Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional
collection INPA-RI
language English
topic Barbus
Characidium
Crenuchidae
Gymnorhamphichthys
Heptapteridae
Imparfinis
Pisces
Rhamphichthyidae
Trichomycteridae
spellingShingle Barbus
Characidium
Crenuchidae
Gymnorhamphichthys
Heptapteridae
Imparfinis
Pisces
Rhamphichthyidae
Trichomycteridae
Zuanon, Jansen
A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
topic_facet Barbus
Characidium
Crenuchidae
Gymnorhamphichthys
Heptapteridae
Imparfinis
Pisces
Rhamphichthyidae
Trichomycteridae
description We studied a specialised assemblage of sand-dwelling fish species from a streamlet in central Amazonia. The five sand-dwelling species comprised 15.2 % of the total number in the streamlet (33 species). Two of the sand-dwellers are daytime foragers, Characidium cf. pteroides (Crenuchidae) and Stauroglanis gouldingi (Trichomycteridae), whereas three ones are night-time foragers, Gymnorhamphichthys rondoni (Rhamphichthyidae), "Imparfinis" pristos and Mastiglanis asopos (Heptapteridae). With the exception of C. cf. pteroides, the remainder species bury in the sand during their resting period. All five species bear a cryptic, sand-colour pattern, and some are translucent, traits which we regard as advantageous both for evasion from predators and for approaching prey (for the daytime foragers). All five species are microphagous carnivores and their foraging tactics range from generalised sit-and-wait (C. cf. pteroides) to active searching for interstitial prey (G. rondoni). A unique "drift-trap" system made up by the extended barbels and filamentous first pectoral-fin rays is employed by M. asopos. We regard the small size and low number of vertebrae (which is functionally expressed by fast displacements in the sand) as additional features advantageous to explore the sand habitat, allowing diving quickly in the substrate to evade predators and to forage for small prey in sand interstices or plant debris. The relationship between morphological and behavioural characters suited to life in sandy substrates is examined under the perspective of the current phylogenies for each group of psammophilous fishes here studied. The mapping of these characters demonstrates that not all of them evolved specifically for strict psammophily. Instead, some of them may represent the final step of a transformation series or synapomorphies of higher hierarchical levels. Several characters linked to psammophily, such as small body, large eyes, and scarce pigmentation are probably paedomorphic traits. We consider that the little variable specific composition of fish sand-dwelling assemblages and the wide (although patchy) geographical distribution of their species in the Amazon are due to the widespread occurrence and low complexity of this specialised habitat. The pre-existence of benthic habits, small size, and the broad distribution of rivers with sandy beds, mainly in the Amazon and Orinoco basins, possibly played a determinant role in the origin and diversification of psammophilous assemblages among freshwater fishes in South America. Copyright © 2006 Sociedade Brasileira de Ictiologia.
format Artigo
author Zuanon, Jansen
author2 Bockmann, Flávio Alicino
Sazima, Ivan
author2Str Bockmann, Flávio Alicino
Sazima, Ivan
title A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
title_short A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
title_full A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
title_fullStr A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
title_full_unstemmed A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes
title_sort remarkable sand-dwelling fish assemblage from central amazonia, with comments on the evolution of psammophily in south american freshwater fishes
publisher Neotropical Ichthyology
publishDate 2020
url https://repositorio.inpa.gov.br/handle/1/14636
_version_ 1787142409117761536
score 11.755432

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