Unraveling one of the ‘Big Five’: update of the taxonomy of Triphoridae (Gastropoda, Triphoroidea) from Brazil

Maurício Romulo Fernandes,Alexandre Dias Pimenta

doi:10.5852/ejt.2020.665

Maurício Romulo Fernandes, Alexandre Dias Pimenta

Open Access

https://doi.org/10.5852/ejt.2020.665

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Abstract

The present study aims to fulfill the gap of taxonomic knowledge on Triphoridae from Brazil. We describe five new species (Isotriphora uncia sp. nov., Isotriphora leo sp. nov., Monophorus verecundus sp. nov., Sagenotriphora albocaput sp. nov., Similiphora lucida sp. nov.), report five species previously known only from the Caribbean and related areas (Cheirodonta dupliniana (Olsson, 1916), Eutriphora auffenbergi Rolán & Lee, 2008, Isotriphora tricingulata Rolán & Fernández-Garcés, 2015, Marshallora ostenta Rolán & Fernández-Garcés, 2008, Monophorus caracca (Dall, 1927) comb. nov.) and describe six morphotypes at the generic level (Isotriphora sp. 1, Marshallora sp. 1, Nanaphora sp. 1, Sagenotriphora sp. 1, Sagenotriphora sp. 2, Similiphora sp. 1). Remarks are made to some species previously recorded from Brazil, including the invalidation of records, problems of generic allocation and geographical range extensions. Maps of the geographical distribution are provided for the 65 currently recognized species of Triphoridae from Brazil. Of these, 31 species are endemic to Brazil and 58 inhabit the continental shelf vs only seven from the continental slope. A distinct geographical zone occurs in southeastern Brazil. A few species occur exclusively near the mouth of the Amazon River, whereas others inhabit a local biogenic reef, possibly serving as a biogeographical corridor that connects western Atlantic populations. Species of Isotriphora from Brazil are particularly common around oceanic islands, probably due to adopting intracapsular metamorphosis, which may have evolved in more than one evolutionary event.

Highlights

Triphoridae Gray, 1847 is a family of marine gastropods, mainly distributed over shallow waters of tropical and temperate regions (Marshall 1983), with some species occurring in the deep sea (Fernandes & Pimenta 2017a)
Descriptions are solely based on shells from Brazil in cases of species that have already been described from other regions
From 2011 to the number increased to 65, revealing the importance of taxonomic revisions to update our knowledge of the real diversity of regional biota

Summary

Introduction

Triphoridae Gray, 1847 is a family of marine gastropods, mainly distributed over shallow waters of tropical and temperate regions (Marshall 1983), with some species occurring in the deep sea (Fernandes & Pimenta 2017a). Triphorids display a huge variation in the composition of the radula (Marshall 1983; Fernandes & Pimenta 2019a), sometimes referred to as “rhinioglossate” because of the presence of several marginal teeth and a peculiar morphological variability of teeth and cusps. Distinctive sculpture of both embryonic and larval shell for species with a multispiral protoconch constitute another remarkable feature of this family (Marshall 1983; Fernandes & Pimenta 2017b)

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