Systematics of Temperate Eastern Pacific Amphiodia Species (Echinodermata ophiuroidea): A Three-Year Study

Lulu W. Wang
Alhambra High School
Grade 12
Los Angeles County
Duane Nichols

Summary Statement
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 Southern California.

CSSF / Projects / CalifSF@usc.edu