Phylum: Mollusca Aplysiopsis enteromorphae Class: Gastropoda Order: Sacoglossa Smith's unwashed-looking sacoglossan Family: Hermaeidae

Description Possible Misidentifications Size: 5 to 25 mm long (Behrens 1980; Sacoglossans differ from most Nudibranchia Trowbridge 1993a); most are 10 mm in their lack of a circlet of gills, and by their (Goddard 1985), some to 15 mm (Gonor rolled, rather than solid rhinophores. They 1961). Illustrated specimen (Coos Bay) 15 also lack oral tentacles, and have a uniseriate mm long. radula (Thompson 1976). Sacoglossans are Color: Yellowish white, with greenish black herbivorous. There are other sacoglossans patches; animal can be almost black: much with dorsal cerata and rolled rhinophores, in local variation (Gonor 1961). Head uniform two families: Limapontiidae and Hermaeidae.. in color, dorsal cerata white or yellow tipped; In the family Hermaeidae there are two rhinophores uniform in color, not veined. species (McDonald 2007): Body: Oblong, flat bottomed; no oral Hermaea vancouverensis is a bay form tentacles or parapodial lobes, but with like Aplysiopsis, but very small (5 mm). It has prominent tail (fig. 1). No circlet of external a triangular brown patch anterior to the gills: order Sacoglossa. Secretion of mucus rhinophores, and a brown collar anterior to and viscous white fluid when disturbed the cerata. Its habitat is in the sea grass (Trowbridge 1993b). Zostera Rhinophores: Prominent; rolled, not solid: Hermaea oliviae (=Aplysiopsis oliviae, order Sacoglossa (fig. 1). (Basal part rolled, =Hermaeina oliviae), a rare and probably distal part simple (Kozloff 1974)). Color more southern species than A. uniform, without system of lines. enteromorphae. It is up to 10 mm long, and Foot: No parapodial lobes (which fold over has a Y-shaped dorsal mahogany line running body in some species); foot extends to form back from the rhinophores. tail (Gonor 1961); narrowly triangular (Clark The Limapontiidae are represented locally 1982). by at least four species (McDonald 2007): Cerata: Dorsal processes: spindle shaped, Placida dendritica (=Hermaea ornata) has inflated, white tipped; 8 - 15 rows of 2 to 4 per long rhinophores and an elongate tail (like row (Gonor 1961) (fig. 1); slightly flattened Aplysiopsis), but its cerata are long and not (Clark 1982). lumpy, and its ground color is pale yellow with Gills: None: order Sacoglossa. a distinct veining of olive. It is quite small (to 8 Eyes: Black, small, but conspicuous; deep mm), and is often found in the green algae set, at bases of rhinophores (fig. 1). Bryopsis and Codium in the rocky intertidal. Genital Openings: Two, on right behind Olea hansineensia (formerly in Oleidae) is rhinophore (fig. 1). greenish brown. It has only 10 or fewer white Anus: Slightly raised, near 2nd and 3rd cerata, tipped cerata; its rhinophores are short. with black spot and near renal opening Stiliger fuscovittatus differs from most (Gonor 1961) (fig. 1). Anus on midline at sacoglossans in having solid simple “shoulders” not on a long tube. rhinophores; it is small (to 3 mm) and whitish, Eggs: Yellow to white, in "C" shaped string 14 with rust markings. It lives in the red alga mm x 15 mm; eggs become paler as they Polysiphonia. develop (Goddard 1984; Gonor 1961). Eggs Alderia modesta (which see) has reduced average 66 µ in diameter (fig. 3) and are ≤ 4 rhinophores and an anus on a long posterior mg (Trowbridge 1993a). Hydrophilic tube like a ceras. It lives in Salicornia (Trowbridge 1993a). marshes.

Bork, E. and Kenton, K. 2017. Aplysiopsis enteromorphae. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR.

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12741 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Ecological Information as free swimming veligers and have long Range: Ketchikan, Alaska to San Diego, planktonic feeding phase (Gonor 1961). California; also in Gulf of California (Behrens Embryonic period 7 days at 15-17 °C.; larvae 1980; Trowbridge 1993b). without eyespots at hatching; newly hatched Local Distribution: Coos County: South veligers have shell about 113 µ long Slough, in Metcalf Preserve, and South Cove, (Goddard 1984). Sexually mature a few days (Trowbridge 2002). after hatching (Trowbridge 1993b). Habitat: Sacoglossans are typically restricted Growth Rate: 10 mg/week or 1.4 mg/day to certain algae species (Gonor 1961; (Trowbridge 1993b). Thompson 1976). In bays, Aplysiopsis is Longevity: commonly found on the green filamentous Food: Prefers Rhizoclonium, Urospora, algae Rhizoclonium and Enteromorpha. It Cladohphora columbiana, Cladophora also likes quiet, shallow mud-bottomed bays trichotoma, Chaetomorpha linum, which have Zostera at low tide level and bare Chaetomorpha aerea (Trowbridge 1993a, mudflats above (San Juan Island). In Coos 2002); prefers Chaetomorpha over Bay it is found on bare mudflats near Cladophora (Trowbridge 1993a); rejects Enteromorpha beds. Also found seasonally Enteromorpha (Gonor 1961). Feeds by slitting on green algae Cladophora and each filament cell with a radular tooth, then Chaetomorpha in high to mid intertidal pools moving on to the next cell (Gonor 1961) (fig. on open coast rocky shores, as well as in kelp 4). Suctorial feeding (Trowbridge 1993a). holdfasts (Goddard 1984; Goddard 1985; Starts at the distal tip and moves toward the Keen and Coan 1974). Not found in areas proximal end of each filament (Trowbridge with high levels of wave action (Trowbridge 1993a). 1993b). Predators: Rarely consumed by most Salinity: Collected at 30. predators, but eaten by mudflat crabs and Temperature: 10-15 °C. Dungeness crabs in experiments (Trowbridge Tidal Level: On San Juan Island, found at 0.0 1994). tide level; in Coos Bay at +5.0 ft. MLLW. Behavior: Some sacoglossans emit Intertidal to 10 m subtidally (Keen and Coan unpleasant repellants from cerata to repel 1974). predators (Thompson 1976). When disturbed, Associates: In Coos Bay, amphipods it reduced surface pH, became acidic, and Ampithoe valida, Grandidierella japonica, alga waved and autotomized cerata (Trowbridge Enteromorpha, isopods, and prosobranch 1994). Attracted to conspecifics; found living gastropods (Trowbridge 2002). near one another (Trowbridge 1993b). Weight: 4-227 mg (wet weight) (Trowbridge 1993b). Bibliography Abundance: Probably the most abundant 1. BEHRENS, D. W. 1980. Pacific coast sacoglossan of this coast (Goddard 1985; nudibranchs: a guide to the Gonor 1961); seasonally common (Goddard opisthobranchs of the northeastern 1984; Goddard 1985; Steinberg 1963); only Pacific. Sea Challengers, Los Osos, sacoglossan species that fills the niche of Calif. eating green filamentous algae (Trowbridge et 2. CLARK, K.B. 1982. A new Aplysiopsis al. 2011). (Opisthobranchia: Hermaeidae) from central Flordia, with a brief summary Life History Information of the ceratiform families of the order Reproduction: Hermaphroditic; produces a ascoglossa (= sacoglossa). Bulletin of single generation per year (Trowbridge 2002); Marine Science. 32:213-219. (illustrated) eggs found July (Coos Bay) with 3. GODDARD, J. H. R. 1984. The recruitment in June (Trowbridge 1993b). Lays opisthobranchs of Cape Arago, eggs on Enteromorpha strands continuously Oregon, with notes on their biology in lab; lays eggs on Mastocarpus papillatus in and a summary of benthic high tidepools and on Enteromorpha in opisthobranchs known from Oregon. mudflats (Trowbridge 2002); larvae emerge Veliger. 27:143-163.

Bork, E. and Kenton, K. 2017. Aplysiopsis enteromorphae. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. 4. ——. 1985. Personal communication. central coast of Oregon, USA. The Oregon Institute of Marine Biology, Veliger. 36:99-106. Charleston, Or. 13. TROWBRIDGE, C.D. 1994. Defensive 5. GONOR, J. J. 1961. Observations on responses and palatability of specialist the biology of Hermaeina smithi, a herbivores: Predation on NE Pacific sacoglossan opisthobranch from the ascoglossan gastropods. Marine west coast of North America. The Ecology Progress Series. 105:61-70. Veliger. 4:85-98. 14. TROWBRIDGE, C.D. 2002. 6. KEEN, A. M., and E. COAN. 1974. Northeastern Pacific sacoglossan Marine molluscan genera of Western opisthobranchs: Natural history North America: an illustrated key. review, bibliography, and prospectus. Stanford University Press, Stanford, The Veliger. 45:1-24. California. 15. TROWBRIDGE, C.D., Y.M. HIRANO, 7. KOZLOFF, E. N. 1974. Keys to the Y.J. HIRANO, K. NISHIDA, and K. marine invertebrates of Puget Sound, SUDO. 2011. North-west Pacific the San Juan Archipelago, and sacoglossan guild associated with adjacent regions. University of filamentous green algae (Family Washington Press, Seattle & London. Cladophoraceae and Family 8. MCDONALD, G.R. 2007 Sacoglossa Boodleaceae). Marine Biodiversity and Nudibranchia, p. 797-798. In: Records. 4:1-15. Light and Smith manual: intertidal invertebrates from central California to Oregon. 4th ed. J.T. Carlton (ed.). University of California Press, Berkeley. 9. STEINBERG, J. E. 1963. Notes on the opisthobranchs of the west coast of North America. The Veliger. 6:68-73. 10. THOMPSON, T. E. 1976. Biology of opisthobranch molluscs. Ray Society, London. 11. TROWBRIDGE, C.D. 1993a. Feeding ecology of the ascoglossan opisthobranch Aplysiopsis enteromorphae (Cockerell & Eliot): Patterns of distribution and impact on tidepool-dwelling algae. Journal of Experimental Marine Biology and Ecology. 169:233-257. 12. TROWBRIDGE, C.D. 1993b. Population structure of two common species of ascoglossan (= sacoglossan) opisthobranchs on the

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12741 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected]