Tardigrades from Larus dominicanus Lichtenstein, 1823 nests on the Argentine Islands (maritime Antarctic)

Łukasz Kaczmarek,Milena Roszkowska,Magdalena Gawlak,Jan Esefeld,Ivan Parnikoza,Iryna Kozeretska,Hans-Ulrich Peter

doi:10.1007/s00300-017-2190-4

Abstract

Tardigrada in Antarctic regions are poorly known. The aim of this study was to examine for tardigrades the nests material of the kelp gull (Larus dominicanus Lichtenstein, 1823) in maritime Antarctic and discuss the possible ways of migration and dispersion of tardigrades by birds. We also discuss the influence of bird’s guano on the communities of microscopic invertebrates (mainly tardigrades). In the positive samples (mainly bryophytes and lichens) of seven Larus dominicanus nests, collected on Ardley Island (near Fildes Peninsula) and Argentine Islands, ca. 850 tardigrades and their eggs were found. In total, 13 taxa (including Ramajendas sp.) were identified, and four are new to science: Bryodelphax olszanowskii sp. nov., Diphascon puchalskii sp. nov., D. rudnickii sp. nov. and Hypsibius conwentzii sp. nov.. Bryodelphax olszanowskii sp. nov. differs from known Bryodelphax species in the weglarskae group mainly by having a different ventral plate configuration. Belonging to the pingue group, D. puchalskii sp. nov. differs from other species by some quantitative characters and D. rudnickii sp. nov. by having the first and second macroplacoids situated very close to each other. Hypsibius conwentzii sp. nov. differs from other species of the genus Hypsibius, with two macroplacoids and septulum, by some morphological and morphometric characters. Summarizing, Antarctic tardigrades are a very diverse group, and birds can be responsible for translocation of small invertebrates (including tardigrades) inside of various parts of plants and lichens. They also deposit large amounts of guano, which provides a lot of nutrients for poor tundra ecosystems and support small invertebrate communities.

Highlights

Antarctica is one of the most extremely unsuited habitats on the planet, with very low temperatures and the lack of liquid water
The aim of this study was to examine for tardigrades the nests material of the kelp gull (Larus dominicanus Lichtenstein, 1823) from two regions of maritime Antarctic (King George Island with neighbouring Ardley Island and Argentine Islands)
Bryodelphax olszanowskii sp. nov Material examined: type material: 46 animals mounted on microscope slides in Hoyer’s medium and 10 animals prepared for scanning electron microscopy (SEM)

Summary

Introduction

Antarctica is one of the most extremely unsuited habitats on the planet, with very low temperatures and the lack of liquid water. Because of variable biological and physicochemical conditions, different regions of the maritime Antarctic may show varied levels of biodiversity (Lindsay 1971; Smith and Corner 1973). These regions are characterized by the highest rates of regional climate warming recorded on the planet, which can result in fast changes in local biodiversity (Turner et al 2005; Convey et al 2009). As of only ca. 30 bdelloid rotifers, ca. 70 monogonont rotifers, ca. nematodes and 62 tardigrades species are known from the entire Antarctic region (e.g. Velasco-Castrillon et al 2014; Vecchi et al 2016), which allows us to suppose that most of the microinvertebrates in this region are still unknown

Objectives

Methods

Results

Conclusion