Firoloida demarestiaRoger R. Seapy
Firoloida is a monotypic genus represented by the cosmopolitan species F. demarestia. It is the smallest (maximal body length of 40 mm) and most transparent species in the family Pterotracheidae. The visceral nucleus is terminal on the trunk, followed by a short ventral tail and either a permanent egg string (in females) or a tail filament (in males). Prominent tentacles and a fin sucker are present in males, but are absent in females.
A pterotracheid with:
- elongated, cylindrical body divided into a proboscis, trunk and a very short tail
- tentacles, fin sucker and tail filament only in males
- permanent egg string in females
- Body morphology
- Body elongate, cylindrical
- Proboscis short relative to the long trunk
- Visceral nucleus terminal on trunk
- Tail ventral and short
- Sexually dimorphic characters
- Permanent egg string extends posteriorly from base of visceral nucleus in females
- Tail filament posterior to visceral nucleus in males
- Sucker small and located on anterior margin of swimming fin in males
- Tentacles prominent, located anterior to eyes in males (see photo below)
- Eye morphology
- Lens capsule oblong, with lens basal and distal portion slightly opaque
- Larval shell (shed at metamorphosis)
Figure. Larval shell of Firoloida demarestia. Left: dorsal view (scale bar = 100 µm). Right: apertural view (scale bar = 50 µm). © 2007 Arie W. Janssen
- Central tooth bears two long, sickle-shaped and pointed posterior processes on its basal plate
Figure. Body regions and selected structures in Firoloida demarestia. ©
Figure. Posterior body region, right side in female Firoloida demarestia. ©
Figure. Dorsal view of right eye in male Firoloida demarestia.©
Lalli, C. M. and R. W. Gilmer. 1989. Pelagic snails. The biology of holoplanktonic gastropod mollusks. Stanford Univ. Press, Stanford, pp. 1-259.
Richter, G. and R. R. Seapy. 1999. Heteropoda, pp. 621-647. In: D. Boltovskoy (ed.), South Atlantic Zooplankton. Leiden: Backhuys Publ.
Tesch, J. J. 1949. Heteropoda. Dana Rep. 34, pp. 1-53.
Roger R. Seapy
California State University, Fullerton, California, USA
Correspondence regarding this page should be directed to Roger R. Seapy at
Page copyright © 2007
- First online 05 June 2007
- Content changed 02 November 2007
Citing this page:
Seapy, Roger R. . 2007. Firoloida http://tolweb.org/Firoloida_demarestia/28736/2007.11.02 in The Tree of Life Web Project, http://tolweb.org/. Firoloida demarestia . Version 02 November 2007 (under construction).