Assessment of larval distribution of invasive Omobranchus punctatus (Valenciennes, 1836) (Pisces: Blenniidae) in a subtropical estuary (Southern Brazil)

Micheli De Paula Costa,Paulo Schwingel,Henry Louis,Jose Souza-Conceicao

doi:10.3391/ai.2011.6.s1.008

Abstract

The occurrence and spatio-temporal distribution of the larvae of exotic Blenniidae Omobranchus punctatus (Valenciennes, 1836) was studied at Babitonga Bay, a subtropical estuary of Southern Brazilian Coast. Samples were collected in 26 ichthyoplankton surveys (28 stations) from April 2004 to August 2008. Oblique hauls were used, with both a conical plankton net fitted with 200µm mesh and by a cylindricalconical plankton net fitted with 500µm mesh (two and five minutes hauls, respectively). Larvae occurred continuously throughout the sampling and an increase in density was observed in the period from November to April. Specimens were registered throughout the study area. The occurrence of a wide range of ontogenetic stages indicates that the species is maintaining the population within Babitonga Bay. The lack of information about the potential impacts of O. punctatus in the ichthyoplankton assembly, with regard to ecological interactions and the food chain suggests the need for further studies.

Highlights

The muzzled blenny Omobranchus punctatus (Valenciennes, 1836) (Pisces: Blenniidae) is a coastal and brackish benthic water fish that can be found close to river mouths or mangroves, tidal pools and rocky areas (Springer and Gomon 1975)
This study aimed to evaluate the occurrence and distribution of O. punctatus larvae in Babitonga Bay
Oblique hauls were used with a 40cm diameter conical plankton net fitted with 200μm mesh and with a 50cm diameter cylindrical-conical plankton net fitted with 500μm mesh, both equipped with a flow-meter (Table 1)

Summary

Introduction

The muzzled blenny Omobranchus punctatus (Valenciennes, 1836) (Pisces: Blenniidae) is a coastal and brackish benthic water fish that can be found close to river mouths or mangroves, tidal pools and rocky areas (Springer and Gomon 1975). The original distribution is presumed to be the Indo-Pacific, from Japan to Persian Gulf, one established population is found in Trinidad since 1980, which has been attributed to the accidental transfer by slave boats. The spread of these populations, occurred, presumably, by ballast water, which could be responsible for the introduction of this species into Venezuela and the Panama Canal (Springer and Gomon 1975; Golani 2004). There are various habitats within the bay such as islands, rocky shores, estuarine beaches, mangroves, salt marshes and rivers (Cremer 2006). The bay works as a shelter for São Francisco do Sul Harbor, active since 1912 (Cremer 2006), the future Itapoá Harbor and important artisanal fisheries territories

Objectives

Methods

Results