Upogebia Pugettensis Class: Malacostraca Order: Decapoda Section: Anomura, Paguroidea the Blue Mud Shrimp Family: Upogebiidae
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Phylum: Arthropoda, Crustacea Upogebia pugettensis Class: Malacostraca Order: Decapoda Section: Anomura, Paguroidea The blue mud shrimp Family: Upogebiidae Taxonomy: Dana described Gebia (on either side of the mouth), two pairs of pugettensis in 1852 and this species was later maxillae and three pairs of maxillipeds. The redescribed as Upogebia pugettensis maxillae and maxillipeds attach posterior to (Stevens 1928; Williams 1986). the mouth and extend to cover the mandibles (Ruppert et al. 2004). Description Carapace: Bears two rows of 11–12 Size: The type specimen was 50.8 mm in teeth laterally (Fig. 1) in addition to a small length and the illustrated specimen (ovigerous distal spines (13 distal spines, 20 lateral teeth female from Coos Bay, Fig. 1) was 90 mm in on carapace shoulder, see Wicksten 2011). length. Individuals are often larger and reach Carapace with thalassinidean line extending sizes to 100 mm (range 75–112 mm) and from anterior to posterior margin (Wicksten northern specimens are larger than those in 2011). southern California (MacGinitie and Rostrum: Large, tridentate, obtuse, MacGinitie 1949; Wicksten 2011). rough and hairy (Schmitt 1921), the sides Color: Light blue green to deep olive brown bear 3–5 short conical teeth (Wicksten 2011). with brown fringes on pleopods and pleon. Rostral tip shorter than antennular peduncle. Individual color variable and may depend on Two short processes extending on either side feeding habits (see Fig. 321, Kozloff 1993; each with 0–2 dorsal teeth (Wicksten 2011). Wicksten 2011). Teeth: General Morphology: The body of decapod Pereopods: Two to five simple crustaceans can be divided into the walking legs. Second pereopod is not chelate cephalothorax (fused head and thorax) and and bears setae on lower segment margins. abdomen. They have a large plate-like Carpus has small spines and merus has a carapace dorsally, beneath which are five single small spine. Pereopods 3–5 setose, pairs of thoracic appendages (see chelipeds decrease progressively in size and have and pereopods) and three pairs of dactyls with spinules (Wicksten 2011). maxillipeds (see mouthparts). The abdomen Chelipeds: First chelipeds and associated appendages are outstretched approximately equal and subchelate (Fig. 1). and shrimp-like in Upogebiidae (Kuris et al. Dactyls curved, with ridged upper surface and 2007). For morphology of Upogebia (see Fig. lateral surface with many tubercles (Wicksten 2, Williams 1986) and U. pugettensis see 2011). Fixed finger slender (Williams 1986), Williams (see Fig. 13, 1986). with one conical tooth. Palm with setose Cephalothorax: lines, bearing setae and small teeth, as well Eyes: Peduncle cylindrical (Schmitt as a sharp spine at dactyl base. Carpus with 1921), eyestalks short but exceeding lateral lateral and longitudinal furrow and spine with rostral process. Corneas terminal and small teeth (4–10), two distal spines and, a directed antero-laterally (Williams 1986). larger marginal spine. The upper margin of Antennae: First segment of the merus is curved and bears spines and antennular peduncle has a sharp tooth at small teeth (5–6). Ischium bears a single ventral border and second segment of small spine (Wicksten 2011). flagellum has small, round disto-ventral spine Abdomen (Pleon): Abdomen elongate and (Wicksten 2011). broad, not reflexed, extended, symmetrical Mouthparts: The mouth of decapod and externally segmented. Bears four pairs crustaceans comprises six pairs of of fan-like pleopods (Fig. 1). appendages including one pair of mandibles Hiebert, T.C. 2015. Upogebia pugettensis. 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/1794/12736 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to [email protected] Telson & Uropods: Telson wide anteriorly habitats. Its rostrum is sharp, with prominent and uropod length exceeds that of the telson. medial tooth (not found in N. californiensis), Uropods bear dorsal ribs and marginal spines and its first chela closes without a gap. It is (Wicksten 2011). Fan-like tail formed by more common in its southern distribution, telson, uropods adapted for swimming. south of Point Conception (Barnard et al. Sexual Dimorphism: The first pleopod is 1980; Kuris et al. 2007; Wicksten 2011). absent in males and is slender, bi-articulating Neotrypaea gigas and N. californiensis also and simple in female U. pugettensis (Williams differ in the morphology of the second 1986). pereopod: In N. californiensis the propodus and dactyl are of equal length and in N. gigas, Upogebiidae-specific Character the propodus is curved and wider than the Burrow: Upogebia pugettensis builds U or Y- dactyl (Kuris et al. 2007). Recent shaped burrows that are firm, permanent and examination of these two species using simple with little branching (unlike Neotrypaea morphological and molecular data suggests californiensis). Burrows extend vertically that the key characters for differentiating about 46 cm, then horizontally 0.6–1.2 m and species is the length of eyestalks and shape up to the surface (MacGinitie 1930; Ricketts of the distal outer edges (Pernet et al. 2010). and Calvin 1971). Often, the entrance will have a gravel plug if the tide is out (Stevens Ecological Information 1928). The walls are smooth and mucus Range: Type locality is Puget Sound, lined (MacGinitie and MacGinitie 1949). For Washington. Known range includes Alaska to figure see MacGinitie (1930). Morrow Bay, California (see Fig. 1, Williams 1986; Wicksten 2011). Southern populations Possible Misidentifications of U. pugettensis become replaced by the Upogebiidae is described by Williams (1986) congener, U. macginitieorum (Kuris et al. and Campos et al. (2009) and the single local 2007). species, Upogebia pugettensis (the blue mud Local Distribution: Oregon estuaries and shrimp) often co-occurs with N. californiensis. sloughs including Alsea, Nestucca, Netarts, Upogebia pugettensis is easy to recognize Yaquina, Coos Bay. because it is larger and its color (bluish and Habitat: Estuarine mudflats (in areas without never red or pink) is strikingly different. Its Zostera, Stevens 1928), in mud or sandy burrows are also more firm and substantial. mud, often with some gravel. In adaptation to The most noticeable morphological difference living in an environment that is relatively low between these species is the first pair of legs: in oxygen, N. californiensis and U. both of which are small, sub-chelate and pugettensis exhibit low metabolic rates and equal in U. pugettensis. Furthermore, its can both survive periods of anoxia. Upogebia rostrum is hairy and has a laterally pugettensis has a higher metabolic rate and compressed and slender tip of the short fixed cannot survive periods of anoxia as well as N. finger of the chela (Wicksten 2011). californiensis (Thompson and Pritchard Characteristics defining the 1969a; Barnard et al. 1980; Zebe 1982). Callianassidae are described by Sakai (1999) Salinity: Collected at salinities of 30. A and Campos et al. (2009). There are three strong hyperosmotic regulator, their lower species locally, Neotrypaea californiensis, N. lethal limit is 3.5 (Thompson and Pritchard gigas and N. biffari (Kuris et al. 2007). 1969b; Barnard et al. 1980). Neotrypaea californiensis can be Temperature: distinguished from the other two species by Tidal Level: Intertidal to shallow subtidal, the lack of a prominent rostrum (present in N. near shore (Wicksten 2011). Mid to lower gigas) and eyestalks that are acute and intertidal of bays (Stevens 1928; Kuris et al. diverging tips of the eyestalks (rather than 2007) and usually lower than N. californiensis. short, blunt and not diverging in N. biffari) Occasionally small individuals occur quite (see Campos et al. 2009). Neotrypaea gigas high in the intertidal (Ricketts and Calvin is larger (to 125–150 mm) than the other two, 1971). and relatively rare in sandy sublittoral Hiebert, T.C. 2015. Upogebia pugettensis. 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. Associates: The blue mud shrimp, Upogebia Hart (1937). Larval development in U. pugettensis, is found overlapping the range of pugettensis proceeds via three zoea stages N. californiensis, though it is generally found and, a final megalopa stage, each marked by in lower intertidal burrows and in muddier a molt (Hart 1937; Puls 2001). Upogebia sediments. Common commensals in ghost pugettensis zoea have rostrum shorter than shrimp burrows include a polynoid worm antennules (1/3 antennule length, compare to Hesperonoe, pinnotherid crabs (Scleroplax Callianassidae), five abdominal segments, glanulata), copepods (Hemicyclops, swimming setae on exopods and maxillipeds, Clausidium), the shrimp Betaeus harrimani, and triangular telson with indentation at the bopyrid isopod lone cornuta, the goby posterior margin with five setae, unlike N. Clevelandia, the echiuroid worm Urechis californiensis, which have a medial tooth at caupo, and the clam Cryptomya californica telson posterior (see paguroid zoeae Fig. (MacGinitie 1934; Kuris et al. 2007; Campos 53.2, Harvey et al. 2014: