Thursday, 21 May 2015

Cephalodasys interinsularis: A new species of Gastrotrich from the Bahamas.


Gastrotrichs are a phylum of minute animals, generally less than a millimetre in length, found in interstitial spaces in sediments (a phylum is the highest classification of organisms below that of kingdom; other animal phyla include Molluscs and Arthropods, the Vertebrates only have the status of a subphylum within the Phylum Chordata, which also includes animals such as Sea Squirts and Lancets). Their small size meant that they went unnoticed until the event of microscopy, with the group not being discovered until the 1860s. Despite this unfamiliarity they seem to be ubiquitous in marine sediments, and are also often found in non-marine settings.

In a paper published in the journal Zootaxa on 16 April 2015, Alexander Kieneke of the Deutsches Zentrum für marine Biodiversitätsforschung, AndreasSchmidt-Rhasea of the Centrum für Naturkunde at the Zoologisches Museum in Hamburg and Rick Hochberg of the University of Massachusetts Lowell describe a new species of Gastrotrich from the Bahamas.

The new species is placed in the genus Cephalodasys and given the specific name interinsularis, meaning ‘between the islands’, as it was discovered in sediments from a sandbank between Lee Stocking Island and Norman’s Pond Cay. Specimens of Cephalodasys interinsularis measured 471 μm in length (if this seems rather precise it is because Gastrotrichs are eutelic, meaning adults have a fixed number of cells), with a body divided into head, neck and trunk regions. The head is pair shaped and separated from the neck by a constriction, the trunk slightly wider than the neck. The body is flat, with a convex ventral side.

Cephalodasys interinsularis,schematic drawings. Left: Ventral view. Right: Combined dorsal and internal view. Abbreviations: an, anus; fo, frontal organ; fop, frontal organ pore; lc, locomotory cilia; me, mature egg; mgp, male genital pore; ov, ovary; ph, pharynx; pp, pharyngeal pores; sc, sensory cilia; TbA, anterior adhesive tubes; TbP, posterior adhesive tubes; TbVL, ventrolateral adhesive tubes; te, testis. Kieneke et al. (2015).

Cephalodasysinter insulariswas found in calcareous biogenic sand (sand made up of shell fragments) at a depth of two meters, alongside a variety of other Gastrotrich species, including members of the genera Macrodasys, Paraturbanella, Tetranchyroderma and Draculiciteria. It is not known if it is also found in other environments.

Cephalodasys interinsularis, light microscopic. (A) Ventral view showing the adhesive tubes and locomotorycilia. (B) Horizontal focal plane showing internal organs. Abbreviations:fo, frontal organ; in, intestine; lc, locomotory cilia; me, mature egg; ov, ovary; ph, pharynx; pp, pharyngeal pores; TbA, anterior adhesive tubes; TbP, posterior adhesive tubes; TbVL, ventrolateral adhesive tubes; te, testis. Kieneke et al. (2015).

See also…

http://sciencythoughts.blogspot.co.uk/2014/05/a-new-species-of-gastrotrich-from-coast.htmlA new species of Gastrotrich from the coast of São Paulo State, Brazil.                              Gastrotrichs are microscopic animals of uncertain affinities, reaching at most 3 mm in size, though most species are far smaller. Less than eight hundred species have been described, living between...
http://sciencythoughts.blogspot.co.uk/2014/05/a-new-species-of-gastrotrich-from.htmlA new species of Gastrotrich from the Atlantic coast of Florida.                                          Gastrotrichs are microscopic animals of uncertain affinities, reaching at most 3 mm in size, though most species are far smaller. Less than eight hundred species have been described, living between sediment particles on the ocean floor, at the bottom of ponds and rivers and in biofilms covering grains of soil. They have flattened bodies covered in cilia, with a through gut but...
A new species of Gastrotrich from KwaZulu-Natal.A new species of Gastrotrich from KwaZulu-Natal.                                                                             Gastrotrichs are microscopic animals of uncertain affinities, reaching at most 3 mm in size, though most species are far smaller. Less than eight...
Follow Sciency Thoughts on Facebook.

No comments:

Post a Comment