Systematics of Temperate Eastern Pacific Amphiodia Species
(Echinodermata ophiuroidea): A Three-Year Study
- Lulu W. Wang
- Alhambra High School
Los Angeles County
- Duane Nichols
- This project correctly identifies and describes Amphiodia
urtica, Amphiodia digitata, Amphiodia periercta, Amphiodia
peloria, Amphiodia barbarae, and a new species.
- The taxonomy of subgenus Amphispina species has
not previously been researched. This, despite the fact that
Amphiodia species dominate the California continental
shelf fauna and are indicator species in pollution studies.
Since Mayr's (1963) biological species concept is difficult to
apply in practice, morphological characteristics alone were
used to distinguish among taxa in this study. Morphological
traits of 164 specimens collected from California, Oregon,
Washington, Alaska, and British Columbia were examined, as well
as appropriate holotypes and paratypes. The nominal species
investigated include A. urtica (Lyman, 1860), A.
digitata Nielsen, 1916, A. periercta H.L. Clark,
1911, A. peloria Bush, 1921, and A. barbarae
(Lyman, 1875). After structures that could potentially be used
to differentiate among the species were identified,
measurements and counts of 28 taxonomic characteristics were
taken. This led to the discovery of an undescribed new species
in the subgenus Amphispina. A. peloria was
found to be a synonym of A. periercta, and A.
barbarae a synonym of A. urtica. A.
urtica has ovoid shaped dorsal arm plates. A.
digitata has relatively few and larger plates on the
dorsal disc surfaces. A. periercta lacks hooked
ventral arm spines. The new species has relatively long arms.
These four species have overlapping ranges. A. urtica
and A. digitata are found from southern California up
north to British Columbia. A. periercta is collected
in Washington and Alaska. The new species ranges from southern
California to central California. Based on the frequency of
incorrectly identified specimens in taxonomic and coastal
survey materials, it appears that the distribution and
abundance of Eastern Pacific Amphiodia species may be
different than previously thought.
- Help Received
- Participant in the Southern California Academy of Sciences
Research Training Program; lab equipment at the Natural History
Museum of L.A. County under the supervisor of Dr. Gordon
Hendler; used scanning electron microscope at University of
CSSF / Projects / CalifSF@usc.edu