Brachionus paranguensis sp. nov. (Rotifera, Monogononta), a member of the L group of the Brachionus plicatilis complex.

Gerardo Guerrero-Jiménez,Roy Neilson,Patrizia Elena Vannucchi,Manuel Elías-Gutiérrez,Marcelo Silva-Briano,Roberto Rico-Martínez,David Roberts,Araceli Adabache-Ortiz

doi:10.3897/zookeys.880.28992

Abstract

The Brachionus plicatilis complex represents the most studied group of rotifers, although the systematics of the species complex has not been completely clarified. Many studies have been conducted trying to explore the diversity within the complex, leading to the recognition of three major morphotypes: large (L), small-medium (SM), and small (SS). Currently six species have been described and classified under these types and another nine taxa have been identified but not formally described. Within the L group, three species have been officially described [B. plicatilis s.s. (L1), B. manjavacas (L2), and B. asplanchnoidis (L3)], while a formal description of L4, unofficially known as B. ‘Nevada’, is still lacking. In the present study, a new species, Brachionus paranguensissp. nov., is formally described and presented as a representative of the L4 clade. The species has been named after a high altitude saline crater lake from Central Mexico, where the specimens were collected. An integrated approach using DNA taxonomy through COI and ITS1 markers, morphology, and ecology was used to confirm the identity of the new species.

Highlights

The presence of multiple cryptic species that have been classified as a single species due to their morphological similarity still represents a major challenge for biologists (Bickford et al 2007; Pfenninger and Schwenk 2007)
The COI alignment that included 665 sequences belonging to members of the L group, collapsed into 146 haplotypes; while ITS1 alignment contained 148 sequences and collapsed into 12 haplotypes
Brachionus paranguensis sp. nov. haplotype was included in the L4 clade unofficially known as ‘Nevada’

Summary

Introduction

The presence of multiple cryptic species that have been classified as a single species due to their morphological similarity still represents a major challenge for biologists (Bickford et al 2007; Pfenninger and Schwenk 2007). The exclusive use of morphology-based identification may be problematic when dealing with taxa that lack clear diagnostic characters. To deal with these difficulties, the use of DNA taxonomy represents a valid tool to help reveal the presence of cryptic diversity within taxa whose systematics is still uncertain (Hebert et al 2004; Hajibabaei et al 2007). In rotifers high levels of cryptic speciation occur (Fontaneto et al 2009; GarcíaMorales and Elías-Gutiérrez 2013) and, in this sense, the Brachionus plicatilis complex represents are good example and one of the best studied groups. The Brachionus plicatilis species complex is composed of three major morphotypes: the large (L), the small-medium (SM) and the small size (SS) types (Ciros-Pérez et al 2001). B. rotundiformis Tschugunoff, 1921 (SS)

Methods

Results

Discussion

Conclusion