Vol. 58, 2019
(update: 2019.09.18; 11.11)
What If Multiple Claw Configurations Are Present in A Sample? A Case Study with the Description of Milnesium pseudotardigradum sp. nov. (Tardigrada) with Unique Developmental Variability
Surmacz, Witold Morek*, and Łukasz Michalczyk
of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian
University, Gronostajowa 9, 30-387 Kraków, Poland.
*Correspondence: E-mail: firstname.lastname@example.org (Morek).
E-mail: email@example.com (Surmacz); LM@tardigrada.net (Michalczyk)
Received 14 June 2019 / Accepted 3
Communicated by Benny K.K. Chan
The tardigrade fauna of Iceland has been a subject of studies since mid XX century. So far, only a single species of the genus Milnesium has been reported from the island, M. tardigradum, which at the time was assumed to have a cosmopolitan distribution. However, the record comes from before the redescription of M. tardigradum, thus the validity of the Icelandic report is questionable. Some species of Milnesium
are characterised by developmental variability, which is most
pronounced in the morphology of secondary branches of claws, exhibited
by shifts in the number of spurs. In this contribution, we present a
case study in which multiple claw configurations (CC) were found in a
single lichen sample from Iceland, indicating the presence of more than
one species and/or ontogenetic variability. To elucidate this puzzle,
we utilised a range of integrative tools, including detailed
morphology, morphometry, barcoding and development tracking. We present
the workflow, which enabled us to collect the data for each
species/morphotype. In result, we revealed the presence of three
species, two characterised by ontogenetic CC change (M. variefidum and a new species) and one with a stable CC (a new species). Here, we describe one of these new species, M. pseudotardigradum, which is extremely similar to M. tardigradum, but can be phenotypically differentiated by a unique, double CC change pattern.
Key words: Cryptic species, Developmental variability, Ontogeny, Pseudocrypsis, Species distribution.
Surmacz B, Morek W, Michalczyk Ł. 2019. What if multiple claw
configurations are present in a sample? A case study with the
description of Milnesium pseudotardigradum sp. nov. (Tardigrada) with unique developmental variability. Zool Stud 58:32. doi:10.6620/ZS.2019.58-32.