Edwardsia handi, Daly, Marymegan & Ljubenkov, John C., 2008

Daly, Marymegan & Ljubenkov, John C., 2008, Edwardsiid sea anemones of California (Cnidaria: Actiniaria: Edwardsiidae), with descriptions of eight new species, Zootaxa 1860, pp. 1-27 : 7-9

publication ID	https://doi.org/ 10.5281/zenodo.183642
DOI	https://doi.org/10.5281/zenodo.5663821
persistent identifier	https://treatment.plazi.org/id/A431015F-FFBE-4B7D-DFCC-106AFC6AF0E6
treatment provided by	Plazi
scientific name	Edwardsia handi
status	sp. nov.

Treatment

Edwardsia handi View in CoL sp. nov.

Figs. 1 View FIGURE 1 , 4 View FIGURE 4 ; Table 1

Diagnosis. With large, protrusive nemathybomes in longitudinal rows between macrocnemes, and introvertable physa. Larger size class of nemathybome nematocysts 100 μm or more in length. Length of whole animal in contraction approximately 10 mm; diameter approximately 2 mm.

Material examined. Holotype: CAS 175201, Morro Bay, San Luis Obispo County, California, 10Sep 2003, intertidal. Paratypes: CAS 175202, collected with holotype (> 10 specimens); CAS 175205, Morro Bay, San Luis Obispo County, California, 1Jul1998, intertidal.

External anatomy. Tentacles filiform, 16, in two cycles of eight. Scapus with large, protruding nemathybomes forming longitudinal rows between macrocnemes ( Figs. 4 View FIGURE 4 A, B). Periderm thin, closely adherent; scapus tan to beige, slightly darker than opaque white capitulum and physa. Mesenterial insertions visible as furrows distally, less prominent proximally. Physa naked, with rugae and central invagination; center may be retracted inside scapus ( Figs. 4 View FIGURE 4 A, F).

Internal anatomy and histology. Parietal and retractor muscles restricted ( Figs. 4 View FIGURE 4 D, E). Retractor muscle branched on both surfaces of mesentery, without distinct pennon ( Fig. 4 View FIGURE 4 E). Branches of retractor widely spaced, variable in height and degree of ramification; branches closer to body wall taller, more ramified. Parietal muscle strong, trianguloid, with ramified lateral branches and relatively thick central lamella ( Fig. 4 View FIGURE 4 D). Gonochoric: all examined specimens either male or female.

Nemathybomes large, single, protrude into epidermis ( Figs. 4 View FIGURE 4 A, B, C). Mesoglea of scapus thicker than that of physa; epidermis thicker on physa than on scapus.

Cnidom. Spirocysts, basitrichs, microbasic p mastigophores, pterotrichs ( Figs. 4 View FIGURE 4 G–N; see Table 1 for size and distribution).

Etymology. Named in honor of Dr. Cadet Hand (1920–2006), the preeminent sea anemone taxonomist and naturalist of the central California coast. Dr. Hand described 11 species of sea anemone and produced a comprehensive monograph of the sea anemones of the central California coast.

Distribution and habitat. Known primarily from intertidal of Morro Bay; similar specimens seen from bays from Elkhorn Slough to Los Angeles harbor (JL pers. obs.). Edwardsia handi may be the ecological replacement for E. californica north of Pt. Conception.

Similar species. Relatively few species of Edwardsia have nemathybomes containing nematocysts of two sizes ( England 1987). In southern California, there are three: E. californica , E. handi and E. olguini . At 100–117 μm, the larger size class of nemathybome nematocysts in E. handi are considerably longer than those of E. californica , E. danica Carlgren, 1921 (46–72 μm: Carlgren 1921), E. neozelanica Farquhar, 1898 (41–56 μm: Carlgren 1924), E. olguini (45.0–59.5 μm: Table 2 View TABLE 2 ), or E. sipunculoides ( Stimpson, 1853) (65–74 μm: Carlgren 1931). These larger and more abundant nemathybome nematocysts are also notably longer than those reported for any species having only one size of nematocyst in the nemathybomes (see England 1987: Table 2 View TABLE 2 ).

Remarks. Based on persample abundance and sample area, E. handi attains scaled local densities that exceed 13,000/m2. In Morro Bay, it cooccurs with burrowing anemones of the genus Peachia Gosse, 1855 (family Haloclavidae ), whose members are easily distinguished from Edwardsia in lacking nemathybomes and in having both more mesenteries and a prominent conchula.