Published December 31, 2009 | Version v1
Taxonomic treatment Open

Ichthydium squamigerum Balsamo & Fregni 1995

Description

Ichthydium squamigerum Balsamo & Fregni, 1995

(Figures 8E–G; Table 3)

Localities: Trösvattnet, Västmanland, Sweden (59º33.211’N; 14º29.232’E); Lake Siljan, Dalarna, Sweden (60º53.039’N; 15º06.467’E); Stora Skuggan, Norra Djurgården, Stockholm, Sweden (59º22.068’N; 18º04.152’E).

Material: 7 specimens, 3 measured.

Character Specimen

1 Balsamo & Todaro (1995) Total body L 125 111–143 Head W 30 33–34 Neck W 25 Na

Body W 35 Na

Furca base W ~15 Na

Furca L 18–19 15–22 Adhesive tube L 10 Na

Pharynx L 32 17–33 Mouth ø Na Na

Furca spine L ~10 8.9–13.5 Anterior sensory bristle L ~20 Na

Posterior sensory bristle L ~22 Na

Remarks: The specimens of I. squamigerum agree well with the morphometric data provided by Balsamo & Fregni (1995). The distribution and shape of the rounded keeled scales at the base of the furca as well as the subrectangular ventral terminal scales also agree with the original description. A peculiar difference between the Swedish and the Italian specimens is that the former lack the bi-keeled scales anchoring the posterior sensory bristles. The bristles originate from papillae instead of scales. Fregni et al. (1998) found I. squamigerum exclusively in freshwater sand. Six of the Swedish specimens were found at a sandy beach at lake Siljan and one specimen in a very small sandy patch at lake Trösvattnet. The findings of I. squamigerum in Sweden are the first records outside Italy where the species was described. PhIJ at U28; ASB at U23; PSB at U78.

Associated gastrotrich fauna: Chaetonotus benacensis Balsamo & Fregni, 1995, C. hystrix Metschnikoff, 1865, C. mutinensis Balsamo, 1978, Lepidodermella squamata and Polymerurus rhomboides (Stokes, 1887).

Character Specimen

Notes

Published as part of Kånneby, Tobias, Todaro, Antonio & Jondelius, Ulf, 2009, One new species and records of Ichthydium Ehrenberg, 1830 (Gastrotricha: Chaetonotida) from Sweden with a key to the genus, pp. 26-46 in Zootaxa 2278 on pages 31-32, DOI: 10.5281/zenodo.191157

Files

Files (2.4 kB)

Name Size Download all
md5:50a17ac4ffec6ce2c055bba36d02ecb3
2.4 kB Download

System files (14.9 kB)

Name Size Download all
md5:eeb4e0b6a3ca695eb50b91a05de03be0
14.9 kB Download

Linked records

Additional details

Biodiversity

References

  • Balsamo, M. & Fregni, E. (1995) Gastrotrichs from interstitial fresh water, with a description of four new species. Hydrobiologia, 302, 163 - 175.
  • Balsamo, M. & Todaro, M. A. (1995) Gastrotrichi del Trentino: le Viotte del Monte Bondone. Studi Trentini di Scienze Naturali - Acta Biologica, 70, 9 - 22.
  • Fregni, E., Balsamo, M. & Tongiorgi, P. (1998) Interstitial gastrotrichs from lotic Italian fresh waters. Hydrobiologia, 368, 175 - 187.
  • Metschnikoff, E. (1865) Ueber einige wenig bekannte niedere Thierformen. Zeitschrift fur Wissenschaftliche Zoologie, 15, 450 - 463.
  • Balsamo, M. (1978) Prime ricerche sui Gastrotrichi dulciacquicoli italiani. Atti della Societa Toscana di Scienze Naturali Memorie, Serie B, 84, 87 - 150 (1977).
  • Stokes, A. C. (1887) Observations on Chaetonotus. The Microscope (Detroit), 7 (1), 1 - 9; 33 - 43.