New records of amphoroid diatoms (Bacillariophyceae) from Cachoeira River, Northeast Brazil

Abstract

Amphoroid taxa have been revised in recent decades. Many species formerly assigned to Amphora have been transferred to other recently proposed genera, as Seminavis (Naviculaceae) and Halamphora (Catenulaceae). In Brazil, there are few studies focused on amphoroid taxonomy. This study presents a taxonomic investigation of five uncommon amphoroid taxa from Brazilian diatom flora: Seminavis pusilla, S. strigosa, Amphora ectorii, Halamphora ghanensis and Halamphora sp. Seminavis strigosa is identical in valve morphology and morphometrical data to Amphora twenteana, and its synonymy is proposed. Seminavis pusilla, poorly found in Brazilian waters, has expanded its distribution. Halamphora ghanensis is a new record to American continent while Amphora ectorii are new to Brazilian aquatic systems. Halamphora sp. has distinct ultrastructural features in relation to similar species and is probably new for science.Keywords: Amphora, Bahia state, coastal river, Halamphora, Seminavis. Novas ocorrências de diatomáceas anforóides (Bacillariophyceae) no Rio Cachoeira, nordeste do Brasil ResumoTáxons anforóides foram revisados nas últimas décadas. Várias espécies, previamente atribuídas a Amphora, foram transferidas para outros gêneros recentemente propostos, tais como Seminavis (Naviculaceae) e Halamphora (Catenulaceae).No Brasil, há poucos estudos com foco na taxonomia das diatomáceas anforóides. Este estudo apresenta uma investigação taxonômica de cinco táxons do grupo, incomuns na diatomoflora brasileira: Seminavis pusilla, S. strigosa, Amphora ectorii, Halamphora ghanensis e Halamphora sp. Seminavis strigosa é idêntica em morfologia e métrica da valva à Amphora twenteana, e a sinonimização destas espécies é proposta. Seminavis pusilla, raramente encontrada em águas brasileiras, tem a sua distribuição ampliada. Halamphora ghanensis é um novo registro para o continente Americano, enquanto Amphora ectorii é uma novidade para sistemas aquáticos brasileiros. Halamphora sp. possui características ultraestruturais distintas em relação a espécies similares e provavelmente seja uma nova espécie para a ciência.

Extensive chloroplast genome rearrangement amongst three closely related Halamphora spp. (Bacillariophyceae), and evidence for rapid evolution as compared to land plants

“…Halamphora (Cleve) Levkov [7] is a recently described genus composed of species formerly assigned to the genus Amphora Ehrenberg ex Kützing. Members of the genus occur across a wide ecological spectrum including fresh to hypersaline habitats [8] from the tropics to the polar regions [9,10], and are known to be prodigious oil producers [11,12]. Although diverse, recent taxonomic treatments [7,8] and broadly sampled molecular phylogenetic analyses [13,14] have combined to make Halamphora one of the most well studied groups of diatoms in terms of phylogenetic systematics.…”

Diatom assemblages (Bacillariophyta) in six tropical reservoirs from southeast Brazil: species composition and spatial and temporal variation patterns

“…Although floristic diatom surveys have been carried out in Brazil (e.g. Ferrari & Ludwig, 2007;Cavalcante et al, 2014;Silva et al, 2016), they are greatly concentrated in the South and Southeast regions of the country (e.g. Moura & Bittencourt-Oliveira, 2004;Bertolli et al, 2010;Faria et al, 2010;Souza-Mosimann et al, 2011;Bes et al, 2012;Bartozek et al, 2013;Nardelli et al, 2014;Marra et al, 2016).…”