Morphology and distribution of two epizoic diatoms (Bacillariophyta) in Brazil

Abstract

Recebido em 20/12/2011. Aceito em 4/07/2012 RESUMO(Morfologia e distribuição de duas diatomáceas (Bacillariophyta) epizóicas no Brasil). As diatomáceas epizóicas em copépodos Pseudohimantidium pacificum e Falcula hyalina foram investigadas em microscopias óptica e eletrônica de varredura, com base em amostras coletadas em diferentes ambientes marinhos da costa brasileira. Pseudohimantidium pacificum é reportada pela primeira vez no Oceano Atlântico Sul Ocidental, ampliando significativamente sua faixa de distribuição geográfica. A espécie ocorreu sobre os copépodos Corycaeus amazonicus e Euterpina acutifrons, e em larvas cypris de Cirripedia. Falcula hyalina utilizou um número maior de hospedeiros, particularmente os copépodos Oithona oswaldocruzii, Pseudodiaptomus richardii e Acartia spp. A morfologia e dados biométricos das valvas de ambas as diatomáceas estiveram dentro dos limites registrados na literatura, incluindo as publicações originais. As duas espécies ocorreram em todas as estações de coleta ao longo da região costeira entre as latitudes 12°S e 28°S. F. hyalina havia sido registrada anteriormente no Oceano Atlântico Sul Ocidental na latitude 31°S.Palavras-chave: epibionte, Pseudohimantidium, Falcula, copépoda, biogeografia ABSTRACT (Morphology and distribution of two epizoic diatoms (Bacillariophyta) in Brazil). The epizoic diatoms Pseudohimantidium pacificum and Falcula hyalina, which live on copepods, were investigated using light and electron microscopes, based on material gathered from different marine environments along the Brazilian coast. Pseudohimantidium pacificum is reported for the first time for the Southwestern Atlantic Ocean, significantly enlarging its range of geographic distribution. This species usually covers the entire body surface of the copepods Corycaeus amazonicus and Euterpina acutifrons, and of cypris larvae of Cirripedia. Falcula hyalina uses a higher number of copepod hosts, particularly Oithona oswaldocruzii, Pseudodiaptomus richardii and Acartia spp. The valve morphology and biometrical data of both diatoms were within the range limits recorded in the literature, including the original publications. Both species occurred in all the sampling stations along the Brazilian coastline stretching from 12°S down to 28°S. Falcula hyalina had already been found as far as latitude 31°S in the Southwestern Atlantic Ocean.

Diatom Epibionts on Amphipod Crustaceans: A Possible Vector for Co-introductions?

“…Although no quantitative analysis was performed, some diatom taxa were dominant such as Tabularia affinis (Kützing) Snoeijs, 1992, Licmophora spp., H. coffaeiformis, and A. helenensis, comprising about 50% of the total diatom composition in the majority of analysed amphipod individuals. While some diatoms are known to be specialised epizoic on planktonic copepods [27], only a few studies have dealt with the growth of diatoms on benthic invertebrates. Usually diatoms of the genera Navicula, Amphora, and Cocconeis are known to occur on several species of cnidarians [28], sponges [29], and gastropods [30,31].…”

The epizoic marine diatom Sceptronema orientale (Licmophoraceae, Licmophorales): epitypification and emendation of specific and generic descriptions

“…Ecology: the species was only found attached on the exoskeleton of marine copepods by Takano (1983), Kimor et al (1992) and Skovgaard & Saiz (2006). Fernandes & Calixto-Feres (2012) analysed epizoic diatoms on several species of copepods and they only found Pseudohimantidium pacificum Hustedt & Krasske in Krasske (1941: 272) on Euterpina acutifrons from Paranaguá Bay, Paraná State, Brazil.…”

Effects of Epibiotic Diatoms on the Productivity of the Calanoid Copepod Acartia tonsa (Dana) in Intensive Aquaculture Systems

“…However, occurrences of microalga epibiosis on copepods were mostly documented with particular focus on epibiont morphology, phylogeny, and distribution (Carman and Dobbs, 1997;Fernandes and Calixto-Feres, 2012;Li et al, 2014;Gómez et al, 2018;Nayak et al, 2021). The impacts of algal epibiosis on copepod reproduction were rarely investigated as yet.…”