Phascolosoma Agassizi Class: Phascolosomatida Order: Phascolosomaformes Pacific Peanut Worm Family: Phasoclosomatidae

Phylum: Annelida Phascolosoma agassizi Class: Phascolosomatida Order: Phascolosomaformes Pacific peanut worm Family: Phasoclosomatidae Taxonomy: The evolutionary origins of can be surrounded by ciliated tentacles, a sipunculans, recently considered a distinct mouth and nuchal organ (Fig. 2) (Rice 2007). phylum (Rice 2007), is controversial. Current Along the introvert epidermis are spines or molecular phylogenetic evidence (e.g., Staton hooks. 2003; Struck et al. 2007; Dordel et al. 2010; Oral disc: The oral disc is bordered Kristof et al. 2011) suggests that Sipuncula be by a ridge (cephalic collar) of tentacles placed within the phylum Annelida, which is enclosing a dorsal nuchal gland. characterized by segmentation. Placement of Inconspicuous, finger-like and not branched the unsegmented Sipuncula and Echiura (Rice 1975b), the 18–24 tentacles exist in a within Annelida, suggests that segmentation crescent-shaped arc, enclosing a heart- was secondarily lost in these groups (Struck shaped nuchal gland (Fig. 2). et al. 2007; Dordel et al. 2010). Mouth: Inconspicuous and posterior to oral disc, with thin flange (cervical collar) Description just ventral to and outside the arc of tentacles Size: Up to 15 cm (extended) and commonly (Fig. 2). 5–7 cm in length (Rice 1975b). The Eyes: A pair of ocelli at anterior end illustrations are from a specimen (Coos Bay) are internal and in an ocular tube (Fig. 4) 13 cm in length. Young individuals are 10–13 (Hermans and Eakin 1969). mm in length (extended, Fisher 1950). Hooks: Tiny chitinous spines on the Juveniles can be up to 30 mm long (Gibbs introvert anterior are arranged in a variable 1985). The illustrated specimen weighed number of dark, colored rings (usually 15–24 approximately 5.3 g (wet weight). in this species) (Fig. 2). The first three rows Color: Dark pigment blotches, dark conical can be small and colorless, while the last two papillae, particularly at posterior end but also can be incomplete (due to wear) (Fisher along introvert (Plate 120, Rice 2007). The 1950). trunk was brown in the illustrated specimen Trunk: The trunk is bulbous, and the skin was thick and rough, the introvert posteriorly pointed and can be divided into was pale, shiny, smooth, and with dark bands longitudinal bands (not always obvious and splotches. The tentacles were light tan exteriorly). When contracted, the trunk is (Fig. 1). peanut-shaped (Fig. 3). Papillae: Papillae are conical glandular Anus: Dorsal, and at anterior-most structures, each with hard round center on a trunk (Rice 2007), the anus is recognizable as platelet (Fig. 1a). Papillae are thickest around a light, raised area (Fig. 1). Intestinal tract is the posterior end and mid dorsally, near the U-shaped (Fig.4). anus. Nephridiopore: Lateral and just Body: Body divided into anterior introvert posterior to anus (Fig. 1). Nephridia are two and posterior trunk regions and the introvert long structures lying freely within the coelom can be retracted entirely into the trunk (Fig. 3) (Fig. 4). (Rice 2007). Body wall divided into Gonads: Occur at origin of ventral longitudinal bands that can be noticeable on retractors (Fig. 4). Sexual products (gametes) outside (Fig. 4). No true segmentation. extruded through nephridiopores (Fig. 1). Introvert: The introvert resembles a neck and is slender and can be extended to be Possible Misidentifications longer than trunk (Fig. 1) (Stephen 1964). It Sipunculans are fairly easily is composed of an anterior oral disc, which distinguished from other worms by their lack Hiebert, T.C. and M. Jarvis. 2015. Phascolosoma agassizi. 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/1794/12653 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] of segmentation and by their peanut-like Golfingiidae is another sipunculan shape when contracted, hence, their common family, characterized by continuous muscle name: peanut worms. The echiurans, or tissue in the body wall (not bands). The spoon worms, are a similar group that are tentacles surround the mouth (unlike the also unsegmented and of a similar size, crescent shaped arc of tentacles in shape and habitat. They have an extensible Phascolosomatidae). The locally occurring spoon-shaped proboscis, however, and a genus is Golfingia. Golfingia (margaritacea) posterior anus (not mid-body, as in margaritacea, a small and threadlike species Sipuncula). Priapula is a small phylum of that is only 25 mm long. It is known (so far) sausage-shaped non-segmented worms. only from Monterey, California (Rice 1975b). Priapulids are predatory worms with a Golfingia pugettensis (from Puget Sound) bulbous spiny proboscis, quite unlike any in (Fisher 1952) is whitish to dark grey, smooth, Sipuncula. Local representatives in the with only inconspicuous papillae. Its introvert Sipuncula are divided into four families: is about half the body length, and is without Sipunculidae, Golfingiidae, Themistidae and hooks (Hyman 1959). the Phascolosomatidae. Members of the Themistidae are Phascolosoma agassizii and its family characterized by tentacles that are long, (Phascolosomatidae) are characterized by a extending and branching (rather than filiform). horseshoe shaped arc of tentacles lying Three species in the genus Themiste dorsal to the mouth by the four retractor (formerly Dendrostomum) occur locally muscles (Fig. 4) and by the longitudinal including T. dyscrita, T. hennahi and T. muscle bands in the body wall (except for the pyroides. Themiste pyroides has black or species Apionsoma misakianum, formerly brown spines on the introvert and tentacles Golfingia hespera). There are 60 species in that form four main stems. Themiste dyscrita the Phascolosoma genus and nearly all are resembles T. pyroides, but the collar at the distinguished by rings of single hooks on the tentacle base is reddish purple in color. introvert (Stephen and Edmonds 1972). Only Themiste hennahi is similar to both species P. agassizii occurs locally. Phascolosoma but has a cylindrical body and lacks collar japonicum, a Japanese species, has been pigment. reported from Vancouver Island. Its trunk papillae have much larger platelets than those Ecological Information of P. agassizii (Fisher 1950). Phascolosoma Range: Type locality is Mendocino, California perlucens, P. rickettsi (=pectinatum), and P. (Schulze et al. 2012). Known range includes puntarenae are eastern Pacific species found Kodiak Island, Alaska, to Bay of San Quintin, from California southward. None of these are Baja California. Also found in western Pacific likely to be found in the Coos Bay area. (Adrianov et al. 2001), although see Schulze Phascolosoma agassizii is readily et al. (2012) for evidence that this large recognizable by its long, pale introvert with geographic range may include many separate dark bands and rows of hooks, its single and cryptic species. crescent of 15–24 finger-like tentacles with Local Distribution: Coos Bay distribution the mouth outside the arc, and by its conical includes Fossil Point, Clam Island and also on papillae on a rough brown trunk. the outer coast, in the rocky intertidal at Cape The Sipunculidae also have well Arago. defined longitudinal muscle bands in the body Habitat: Individuals nest or burrow in rock wall, but their oral tentacles completely and gravelly mud (but without a permanent surround the mouth (Stephen and Edmonds tube). Also found amongst shells, holdfasts, 1972; Rice 2007). Two species occur locally under rocks or in cracks with Phyllospadix (Siphonosoma ingens and Sipunculus nudus) roots and the hydrocoral, Allopora, in Mytilus and both have a short introvert, numerous beds and protected situations. Not found in tentacles and tend to be larger than P. shifting sediments (Fisher 1950). agassizii at 12–50 cm (P. agassizii is usually Salinity: Collected at 30 in Coos Bay. 5–7 cm) (Rice 2007). Temperature: Temperate to warm waters. Hiebert, T.C. and M. Jarvis. 2015. Phascolosoma agassizi. 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. Tidal Level: From mid intertidal down to 60 (lecithotrophic) trochophore at 2.5 days with a m, but most common in the lower half of the thick egg envelope, followed by a intertidal zone and just below low tide (Fisher planktotrophic pelagosphera, with the addition 1950). of a metatrochal band of locomotory cilia at Associates: Known associates include terminal end of larva (Rice 1987; see Fig. 1, 2 several polychaetes (Thelepus and Glycera), in Johnson 2001; Fig. 19.1–19.11 in Jaeckle chitons, serpent stars, shore crabs, and Rice 2002). Larvae feed at 8–10 days gastropod, Nucella. (Rice 1987), can be teleplanic and develop for Abundance: The most common sipunculan up to several months in the plankton (Rice (California, Rice 1975b) from Alaska to Pt. 1980), however, in culture, larvae form Conception (Rice 1974). attachment with dish soon after beginning to feed (9–10 days, Rice 1987). Some larvae Life-History Information were kept up to seven months, grew to 1 mm, Reproduction: Separate sexes. Ripe individuals found with eggs January but did not metamorphose into benthic (Humboldt Bay, CA) (Fisher 1950), March– juveniles (Rice 1967; Adrianov et al 2011). May (Monterey, CA), June–September (Puget Juvenile: Post-metamorphosis, juveniles Sound, WA) (Rice 1975a). Mature gametes have enlarged papillae, especially in the pre- can compose 37% dry mass of animal. anal area. Pigment includes transverse Gametes are extruded from nephridiopores bands on the introvert, but trunk pigment into seawater, where fertilization takes place. spots are rare. Introvert hooks include 12–25 Of 200 specimens collected Humboldt Bay in rings (usually 15–16).

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