|
Vol. 48 No. 6, 2009
Naupliar Development among the Tisbidae (Copepoda:
Harpacticidae) with a Phylogenetic Analysis and Naupliar Description of
Tisbe thailandensis from
Thailand
Hans-U
Dahms2, Supawadee Chullasorn3, Nikolaos V. Schizas4, Pawana Kangtia4,
Wongpiya Anansatitporn4, and Wan-Xi Yang1,*
1College
of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
2Green Life Science Department, College of Natural
Science, Sangmyung University, 7 Hongji-dong, Jongno-gu, SEOUL 110-743,
South Korea
3Department of Biology, Faculty of Science,
Ramkhamhaeng University, Bangkok 10240, Thailand
4Department of Marine Sciences, University of Puerto
Rico, Mayagüez Campus, Isla Magueyes Laboratories, P.O. Box 908,
Lajas, PR 00667, USA
Hans-U
Dahms, Supawadee Chullasorn, Nikolaos V. Schizas, Pawana Kangtia,
Wongpiya Anansatitporn, and Wan-Xi Yang (2009) Ovigerous females
of a recently described species Tisbe
thailandensis were collected from the seaweed Enteromorpha clathrata on the
eastern coast of Thailand and cultured in the laboratory. Six
naupliar stages are described, and a key to the identification of the
stages is provided. An unweighted analysis of the character
matrix yielded a single most parsimonious tree with a length of 27, a
consistency index of 0.778, a retention index of 0.786, and a rescaled
consistency index of 0.611. There were 15 parsimoniously
informative characters. The resulting cladogram, using nauplii
from the harpacticoid genus Tachidius
(Giesbrecht, 1881) for the outgroup comparison, supports the hypothesis
that T. gracilis is the
sister taxon of T. cucumariae
(both of which belong to the T. gracilis group), and that T. battagliai
is the sister taxon of T. holothuriae
(both of which belong to the T.
holothuriae group), with Tisbe
thailandensis adjoining the T.
gracilis group on an underived branch. Naupliar
comparisons of copepodid morphology provided the greatest number of
phylogenetically useful additional characters since copepodids
essentially foreshadow the adult condition. Limits of the utility
of naupliar characters for phylogenetic inference studies were
apparent, as well as their potential and importance for future work in
zoological systematics. It was shown that phylogenetic
relationships of tisbids are difficult to evaluate on a morphological
basis alone, because of the comparatively small morphological
differences among them. However, more specific morphological
characters can be found, provided studies are detailed enough and
different stages of a sufficient number of species are known to allow
meaningful comparisons.
Key words: Phylogenetic
systematics, Naupliar characters, Ontogeny, Morphology, Tisbidae.
*Correspondence: Tel: 86-137-77863192. Fax:
86-571-88206485. E-mail:wxyang@spermlab.org
|
