Pelagic tunicates in the China Seas
Author
Franco, P.
Author
Dahms, H. - U.
Author
Lo, W. - T.
Author
Hwang, J. - S.
text
Journal of Natural History
2017
2017-03-27
51
15 - 16
917
936
http://dx.doi.org/10.1080/00222933.2017.1293180
journal article
10.1080/00222933.2017.1293180
1464-5262
5180954
Thalia democratica
Morphology
Length of the aggregated zooids of this salp is
1.8–18.2 mm
. Lengths of solitary zooids are
2.3–11.7 mm
. Aggregate form is characterised by an anterior end of the body which is rounded and by a posterior end which is somewhat fusiform. Testis is never echinate, and is pentagonal. Nucleus with a posterior projection. Testis pentagonal posteriorly. Number of muscle fibres in MI–MV is15–17. Atrial opening not central, with a posterior lateral protuberance on one side only. Solitary forms with a smooth test and simple atrial palps. Lateral projections are small, medio-ventral ones are small and of unequal length and anterior projections are smallest. All test projections are echinate. MI to MIV are continuous dorsally and ventrally; MV is interrupted ventrally.
MII
–MIV and MV–MVI converge mid-dorsally over a short distance. Stomach extends partly into the middle posterior projection (authors’ personal observations; (
Marine Species Identification Portal 2017
);
Godeaux et al. 1998
).
Biogeography
Cosmopolitan, eurythermic species from warmer waters; roughly occurring between ca.
60°N
and
40°S
. Also present in the Mediterranean Sea. Epipelagic, living in the upper
100 m
; does not perform diurnal vertical migration (WoRMS
Editorial Board 2017
).