January-April, 2013 
SCAMIT Newsletter 
Vol. 31 Nos. 5-6 
Amphiodia urtica has small, numerous scales on the disc cap and can have some hyaline 
forks or spines that are limited in location to the area around the genital slits. The dorsal arm 
plates are rhomboid-shaped, so that comers of the plates are separated/not touching, thereby 
showing underlying arm tissue. Examples of possible hybridization (between A. urtica and A. 
digitata, or...?) are referred to A. urtica in the CSD Lab when there is question as to the proper 
identification. 
Amphioplus strongyloplax is found in deeper water in the SCB, but in shallow depths in northern 
waters. A. strongyloplax do not have hyaline cross-bars (T-shaped) on the tips of the proximal to 
medial arm spines, distinguishing it from Amphioplus sp A which does have them. Large radial 
shields also distinguish it from Amphioplus sp A. Megan made a special note for Amphioplus 
specimens from deep water (>200m): disc diameters need to be > 3 mm before a specific 
identification should be attempted, as the hyaline cross-bars of Amphioplus sp A aren’t always 
developed on small juveniles. 
Amphiura arcystata is usually clearly distinguished from most taxa, but could be confused 
with juvenile Amphioplus. Consequently, if the buccal scales remain appressed to the jaw, then 
back-off to Amphiuridae. The oral papillae pattern of A. arcystata consists of a single pair of 
infradental papillae and the buccal scales that are well separated from the jaw (at angle to jaw). In 
contrast, Amphioplus will develop one or two additional pairs of oral papillae (two or three total) 
distal to the buccal scale if the specimen is developed to where the buccal scale is separated from 
jaw. 
We paused the species review here to discuss the general limitations on the use of color patterns 
because specimens from San Diego (and other areas) do not always show the same depth and 
richness of color as specimens from some of the northern communities (e.g., Santa Monica Bay, 
Goleta, etc). 
Amphipholis pugetana vs. A. squamata - In A. pugetana the median arm spines are like large 
paddles (thickened and distally fiattened, fiaring at the tip) and longer than the dorsal and ventral 
spines which is in contrast to the relatively narrow, evenly tapered and subequal arm spines of A. 
squamata. Again, as with most ophiuroids, growth stage is a factor in the development of these 
distinctive character states. 
Ophiopsila californica has pigment on the disc as well as pigmented arm plates. It has round, 
blunt arm spines, and extremely long tentacle scales which are so large that they can be mistaken 
for tube feet or ventral arm spines. As adults O. calif ornica has oral teeth (not papillae), but 
as juveniles, it appears to have an oral papillae pattern similar to Amphiura arcystata or an 
Amphioplus. Closer inspection reveals this not to be the case, but caution must be used with 
juveniles. Based on feedback from other agencies (Don Cadien, LACSD) the species is typically 
associated with hard bottom, or rubble having been dislodged from reef material and therefore is 
rarely seen, at least in CSD samples. 
Several species of Ophiura are possible: O. luetkenii, O. leptoctenia, and O. sarsi. The MMS 
Atlas Volume 14 (1996) distinguishes O. luetkenii and O. leptoctenia, however, it omits O. sarsi. 
O. sarsi is separated from the other two by the nature of the spines in the arm comb. Megan feels 
that we probably do not see O. sarsi this far south as it is mostly recorded from the Bering Sea 
and Japan, but she suggested taxonomists use caution when looking at Ophiura from unusual 
locales and depths (see Clark 1911, D’Yakonov 1954, and Lambert 2007 for further discussion of 
Ophiura). [M. Lilly update July 2016:1 specimen of O. sarsi was recorded from B'13 sampling]. 
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Publication Date: 28 July 2016 
