Brachionus rotundiformis Tschugunoff, 1921 from the Brachionus plicatilis species complex (Rotifera: Monogononta): A new record from Galápagos Archipelago, Ecuador

Carlos López,Diego Fontaneto,Evangelia Michaloudi,Georgia Stamou,Hendrik Segers,Miriam Steinitz-Kannan,Spiros Papakostas

doi:10.11606/1807-0205/2019.59.21

Abstract

The presence of the rotifer species Brachionus rotundiformis from the B. plicatilis species complex in Lake Arcturo, a saline lake in the Genovesa Island of the Galápagos Islands, is here reported. This is the first record of the species for the rotifer fauna of Ecuador as well as of the species complex to the Galápagos Islands. This finding is consistent with the idea of high dispersion capacity, and of cosmopolitan distribution of this species complex. Because Genovesa Island is uninhabited, passive transport by wind currents and zoochory by migrant birds seem to emerge as the most plausible factors in this process of colonization. Integrative studies on the morphological variations, genetic, molecular, and ecological aspects are still required to further understand the process of dispersion and the ecology of this member of the B. plicatilis species complex in this remote and isolated locality, and the exact taxonomical position of the island’s population to the other members of the complex.

Highlights

Brachionus plicatilis Müller, 1786 is one of the best known monogonont rotifers
The presence of the rotifer B. rotundiformis from the B. plicatilis species complex is reported in Lake Arcturo, a saline crater lake located on Genovesa Island, the Galápagos Archipelago, Ecuador
Analyzed material was collected at Lake Arcturo (WGS84 coordinates: 00°19’40”N, 89°57’30”W) which sits at sea level on the center of Isla Genovesa, an uninhabited, 17 km2 island located in the northeastern Galápagos Archipelago (Fig. 1)

Summary

Introduction

Brachionus plicatilis Müller, 1786 is one of the best known monogonont rotifers. This taxon has been extensively studied, owing to its successful use in aquaculture (Lubzens, 1987; Lubzens et al, 2001) and ecotoxicology (Kostopoulou et al, 2012; Rico-Martínez et al, 2017; Won et al, 2017) and presently constitutes a model organism in ecological and evolutionary studies (Declerck & Papakostas, 2017; Serra & Fontaneto, 2017).Traditionally, B. plicatilis has been considered a cosmopolitan morphologically variable taxon associated to saline waterbodies The presence of the rotifer species Brachionus rotundiformis from the B. plicatilis species complex in Lake Arcturo, a saline lake in the Genovesa Island of the Galápagos Islands, is here reported. This is the first record of the species for the rotifer fauna of Ecuador as well as of the species complex to the Galápagos Islands.

Results

Conclusion