Redescription of the dasydytid gastrotrich Haltidytesooëides (Brunson, 1950) based on type material.

Axell K Minowa,André R S Garraffoni

doi:10.3897/zookeys.785.28382

Abstract

The semi-pelagic gastrotrich species Haltidytesooëides (Brunson, 1950) is redescribed based on original type material deposited at the Smithsonian National Museum of Natural History. Herein we present a new diagnosis and figures of the species, detailing the insertion position of the lateral spines, misinterpreted in the original description. Furthermore, we reassess the taxonomic key for the genus Haltidytes Remane, 1936 based on our new findings.

Highlights

While most gastrotrichs are epibenthic, periphytic, or interstitial, some species belonging to the family Dasydytidae Daday, 1905 present a semi-pelagic lifestyle (Kieneke et al 2008, Balsamo et al 2014, Kånneby and Todaro 2015)
Trunk locomotory ciliation divided into 2-paired ventral tufts at 15U and 93U on the ventral side of at the neck and posterior trunk, respectively (Figure 2C, D)
After reexamination of the type specimen (Figure 2A, B–D) we conclude that Brunson (1950) may have misinterpreted these structures

Summary

Introduction

While most gastrotrichs are epibenthic, periphytic, or interstitial, some species belonging to the family Dasydytidae Daday, 1905 present a semi-pelagic lifestyle (Kieneke et al 2008, Balsamo et al 2014, Kånneby and Todaro 2015). The observed specimen has a compact, bowling pin-shaped body, measuring 88 μm in total body length, 184 μm with spines included. Trunk ovoidal in shape (42 μm in maximum width) with a rounded posterior end (Figure 1A).

Results

Conclusion