Análises morfométricas dos peixes da família Ostraciidae da costa Nordeste do Brasil.

Abstract

Known as boxfish, the members of the Acanthostracion quadricornis, Acanthostracion polygonius and Lactophrys trigonus species are all part of the order Tetraodontiforme, family Ostraciidae. They present as a striking feature a body enclosed in a bony box with hexagonal plates, which is one of the reasons they are so easily recognizable, leaving only their fins, eyes and mouth on the outside of the box. All three species are distributed across the Atlantic in tropical and temperate waters and from the USA to Bermuda, the Caribbean, and from the Antilles to Brazil, where their distribution is wide, as they are found in the waters of the North and Northeast coasts, where large populations of these species are found in Brazil. They are marine animals associated with coral reefs, being found in depths of up to 80 m. This thesis´ objectives are limited to knowing more about the morphometry (relatively little is known about it) as well as the length-length relationships of these species, in addition to knowing if there are significant differences between two genera of the same family and the effects of the environment on the body of these fishes. This work provides information about a possible influence of body shape on the distribution of these species in relation to the shelf environments of the northeast region of Brazil. Caught individuals of each species were used to generate linear models, generating length-length relationships (LLR). The data obtained and used does not show a significant relationship between the distribution of species, regarding depth, habitats nor for the shape of their bodies. Body shape varied according to species, meaning possibly existing another mechanism, one with greater influence than the analyzed agents, affecting the shape of the body.