Short Communication |
Corresponding author: Alexey Polilov ( polilov@gmail.com ) Academic editor: Jan Klimaszewski
© 2015 Alexey Polilov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Polilov AA (2015) How small is the smallest? New record and remeasuring of Scydosella musawasensis Hall, 1999 (Coleoptera, Ptiliidae), the smallest known free-living insect. ZooKeys 526: 61-64. https://doi.org/10.3897/zookeys.526.6531
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The smallest known beetle Scydosella musawasensis Hall is recorded for the second time. Precise measurements of its body size are given, and it is shown that the smallest examined representative of this species has a length of 325 µm.
Smallest beetle, body size, SEM, Colombia
The smallest insects have recently attracted considerable attention as models for studying animal miniaturization, since they are among the smallest metazoans and since many morphological features unique to them and resulting from their extremely small size have been described (
Adults of Scydosella musawasensis Hall, 1999 were collected in Chicaque National Park, Colombia, 10 km west of Bogotá, on 8 February 2015 (coordinates 4.619, -74.312), 2200 m above sea level, on the fungus Steccherinum sp. (Meruliaceae), 85 specimens. The material was fixed in FAA (formaldehyde—alcohol—acetic acid) and preserved in 70% ethanol. It was subsequently examined under a Jeol JSM-6380 scanning electron microscope (SEM) after drying of the specimens at the critical point (Hitachi HCP-2) and sputter coating with gold (Giko JSM-6380). The measurements were made using the program Meazure (C Thing Software) from digital micrographs obtained under SEM.
Measuring of ten specimens of S. musawasensis has shown that the smallest of them has a length of 325 µm, the largest has a length of 352 µm, and the average length is 338 µm (Fig.
The record of S. musawasensis in Colombia considerably broadens the known range of this genus and species, known previously only from one site in Nicaragua (
This genus and the only described species it includes differ from the other Nanosellini in the following combination of characters. Body elongate-oval (Fig.
This study has been supported by the Russian Science Foundation (project no. 14-14-00208).