Hiebert, T.C. 2015. Heptacarpus paludicola. 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. Taxonomy: Local Heptacarpus species (e.g. H. paludicola and H. sitchensis) were briefly considered to be in the genus Spirontocaris (Rathbun 1904; Schmitt 1921). However members of Spirontocaris have two or more supraorbital spines (rather than only one in Heptacarpus). Thus a known synonym for H. paludicola is S. paludicola (Wicksten 2011). Description Size: Individuals 20 mm (males) to 32 mm (females) in length (Wicksten 2011). Illustrated specimen was a 30 mm-long, ovigerous female collected from the South Slough of Coos Bay. Color: Variable across individuals. Uniform with extremities clear and green stripes or speckles. Color can be deep blue at night (Bauer 1981). Adult color patterns arise from chromatophores under the exoskeleton and are related to animal age and sex (e.g. mature and breeding females have prominent color patters) (Bauer 1981). Five morphs were described by Bauer (1981) for both H. sitchensis and H. paludicola, including four color morphs and one transparent morph. Adults may exhibit camouflaging colors based on surrounding algae (Bauer 1981), but color patterns may be more or less fixed (genetically) and variably expressed in different environments (Bauer 1982). General Morphology: The body of decapod crustaceans can be divided into the cephalothorax (fused head and thorax) and abdomen. They have a large plate-like carapace dorsally, beneath which are five pairs of thoracic appendages (see chelipeds and pereopods) and three pairs of maxillipeds (see mouthparts) (Kuris et al. 2007). The abdomen and associated appendages are outstretched in Heptacarpus species and the abdomen usually has a sharp bend (“broken-back shrimp” Kozloff 1993). Cephalothorax: Eyes: Antennae: Antennal scale never much longer than rostrum. Antennular peduncle bears spines on each of the three segments and stylocerite (basal, lateral spine on antennule) does not extend beyond the first segment (Wicksten 2011). Mouthparts: The mouth of decapod crustaceans comprises six pairs of appendages including one pair of mandibles (on either side of the mouth), two pairs of maxillae and three pairs of maxillipeds. The maxillae and maxillipeds attach posterior to the mouth and extend to cover the mandibles (Ruppert et al. 2004). Third maxilliped without expodite and with epipods (Fig. 1). Mandible with incisor process (Schmitt 1921). Carapace: No supraorbital spines (Heptacarpus, Kuris et al. 2007; Wicksten 2011) and no lateral or dorsal spines. Rostrum: Well-developed, longer than carapace, extending beyond antennular peduncle (Fig. 2). Rostral teeth include both dorsal (6–8, seven in current specimen, Fig. 1) and ventral (2–4, two in current specimen, Fig. 1). Dorsal edge of rostrum straight, not curved with anterior teeth. Teeth: Rostral teeth present (see Rostrum). Pereopods: Pereopods 1–2 with epipods. Epipod morphology is particularly relevant to the genus Heptacarpus and species with a higher number are considered ancestral to the group (Bauer 1984b). Pereopods 3–5 with bifid dactyls with spines arranged as follows: merus of pereopod three with five spines, pereopod four with four spines and pereopod five with 2–4 spines (Wicksten 2011). Second legs chelate, nearly equal, with seven annulations on carpus (Fig. 1). Chelipeds: Equal, chelate (Fig. 1). Abdomen (Pleon): Shrimp-like, with fantail, body laterally compressed. Side plates of second segment overlap those of first with Heptacarpus paludicola A broken back shrimp Phylum: Arthropoda, Crustacea Class: Malacostraca Order: Decapoda Section: Caridea Family: Thoridae A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12712 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: oimbref@uoregon.edu Hiebert, T.C. 2015. Heptacarpus paludicola. 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. sharp bend (Fig. 1). The third segment without hump and the sixth segment is shorter than telson (Fig. 1). Segments 1–3 with pleura that is rounded, fourth segment with tooth and fifth with spine (Wicksten 2011). Telson & Uropods: Telson bears 4–5 pairs of dorso-lateral spines (Wicksten 2011) (Fig. 1). Sexual Dimorphism: Females often have broader and larger bodies than males, which have compressed and squat bodies (Wicksten 2011). Possible Misidentifications The family Hippolytidae was split into three families following a cladistic analysis by Christoffersen (1987) that are currently recognized by some (e.g. Wicksten 2011), but not all authors (e.g. Kuris et al. 2007). These three families include the Lysmatidae, Hippolytidae and Thoridae. The Lysmatidae are characterized by very long antennular flagella. The three families can further be distinguised by the number of carpal articles on the second pereopod: 22 or more in Lysmatidae, three in Hippolytidae and seven in Thoridae. In addition, Thoridae and Hippolytidae can be differentiated by their supraorbital spines, one in the latter and 0–4 in the former family (Wicksten 2011). The Lysmatidae is represented by a single species locally, Lysmata californica (Kuris et al. 2007; Wicksten 2011). When following the above taxonomy (Christoffersen 1987; Wicksten 2011), local members of the Hippolytidae include Hippolyte californiensis and H. clarki. Meanwhile, the genus Heptacarpus, with eleven local species, falls within the Thoridae, as do the local species Lebbeus lagunae and Spirontocaris prionota (Kuris et al. 2007; Wicksten 2011). Very close in color, morphology, and habitat preference is Heptacarpus sitchensis, whose adult rostral teeth are 4–8/0–5, but whose rostrum, while it can reach to the middle of the antennal scale, does not reach to the end of the scale as does that of H. paludicola. The rostral teeth are closer together on H. sitchensis and the rostrum is more slender (Schmitt 1921), as well as being only equal to or shorter than the carapace. Our H. sitchensis specimens were only 1.5 cm, half the size of the female H. paludicola. Heptacarpus sitchensis is the most commonly found transparent shrimp in tide pools (Ricketts and Calvin 1971), while H. paludicola is more common in mudflats and in eelgrass. Heptacarpus taylori, also has a short rostrum, reaching just to the eye and is often brightly colored, with a series of teeth from anterior carapace margin to the apex. Heptacarpus brevirostris, with smooth rostrum (without lower teeth) that reaches only the first segment of the antennal peduncle. The merus of H. brevirostris has a single spine on pereopods 3–4. Heptacarpus palpator is similar to Heptacarpus brevirostris, but with a longer rostrum that can be di- or trifid, and a longer antennal scale (Wicksten 1986). Heptacarpus stimpsoni, from Puget Sound, has rostrum that extends over eye (only slightly), with dorsal teeth and pereopod (3–5) dactyls that are simple and curved. Heptacarpus carinatus is a long-rostrumed shrimp, with distal rostral teeth (3–7 dorsal and 2–6 ventral) and epipods present on pereopods 1–3. Heptacarpus franciscanus, from San Francisco Bay, has a rostrum longer than the carapace. Heptacarpus pugettensis, H. flexus, and H. tenuissimus have a hump on the third abdominal segment. Heptacarpus pugettensis has epipods on pereopods 1–2 and a rostrum that just reaches the end of the first segment of antennular peduncle and not beyond. Heptacarpus flexus is morphologically similar to H. carinatus, but with epipods on pereopods 1–2 only and a narrow rostrum with teeth (4–5 dorsal and 5– 8 ventral). Heptacarpus tenuissimus lacks teeth on the ventrum of the fourth abdominal pleon and also lacks an exopod on the third maxilliped (see dichotomous key in Wicksten 2011 for Heptacarpus species). Ecological Information Range: Type locality is Humboldt Bay, California. Known range includes Tava Island, Alaska to San Diego, California (Schmitt 1921; Wicksten 2011). Local Distribution: Coos Bay distribution near, and south of, the Charleston Bridge in South Slough. Habitat: South Slough amongst mud and eelgrass (Zostera, Ulva), also on pilings, A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12712 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: oimbref@uoregon.edu floats and in tide pools of outer coasts (Kuris et al. 2007; Wicksten 2011). Salinity: Collected at salinity 30. Temperature: Tidal Level: Collected at +0.15 m and is intertidal to 10 m depths (Wicksten 2011). Associates: Abundance: Common to abundant (Schmitt 1921; Kuris et al. 2007). Life-History Information Reproduction: Ovigerous female found in March, in South Slough, Coos Bay. Males and females may be (weakly) attracted to each other with sex phermones (Bauer 1979), but are generally only triggered to initiate copulation after physical contact (Bauer 2011). Little is known about the development in Heptacarpus species (Strathmann 1987; Puls 2001). Larva: Larval development in Heptacarpus species proceeds via a series of zoea, and, a final, post-zoea (decapodid) stage, each marked by a molt (Puls 2001; Guerao and Cuesta 2014). The zoea are planktotrophic, have a narrow rostrum (without teeth), cylindrical eyestalks, antennule bases that are close together (but not touching), and abdomen with postero-lateral spines (Puls 2001; see Fig. 48.3, Guerao and Cuesta 2014). Juvenile: Longevity: Growth Rate: Growth occurs in conjunction with molting. In pre-molting periods the epidermis separates from the old cuticle and a dramatic increase in epidermal cell growth occurs. Post-molt individuals will have soft shells until a thin membranous layer is deposited and the cuticle gradually hardens. During a molt decapods have the ability to regenerate limbs that were previously autotomized (Kuris et al. 2007). Food: Carnivorous (Kozloff 1993). The majority of caridean shrimps are omnivorous (Chace and Abbott 1980). Predators: Fish. Behavior: Propel themselves backward by flexing their tails forward and often flip out of a collector’s hand. Members of the genus Heptacarpus have been shown to exhibit body, gill and embryo grooming in response to microbial fouling and parasites. Grooming with specialized antennal brushes is found in members of the Stenopodidea, Caridea and Dendrobranchiata and suggests a common ancestor rather than evolutionary convergence (see Bauer 1989). Bibliography 1. BAUER, R. T. 1979. Sex attraction and recognition in the caridean shrimp Heptacarpus Paludicola (Holmes) (Decapoda, Hippolytidae). Marine Behaviour and Physiology. 6:157-174. 2. —. 1981. Color patterns of the shrimps Heptacarpus pictus and Heptacarpus paludicola (Caridea, Hippolytidae). Marine Biology. 64:141-152. 3. —. 1982. Polymorphism of color pattern in the caridean shrimps Heptacarpus pictus and Heptacarpus paludicola. Marine Behaviour and Physiology. 8:249-265. 4. —. 1984. Morphological trends in the genus Heptacarpus (Decapoda, Caridea) and their phylogenetic significance. Journal of Crustacean Biology. 4:201-225. 5. —. 1989. Decapod crustacean grooming: functional morphology, adaptive value, and phylogenetic significance. Crustacean Issues. 6:49- 73. 6. —. 2011. Chemical communication in decapod shrimps the influence of mating and social systems on the relative importance of olfactory and contact pheromones. Chemical Communication in Crustaceans:277- 296. 7. CHACE, F. A., D. P. ABBOTT, R. H. MORRIS, and E. C. HADERLIE. 1980. Caridea: the shrimps. In: Intertidal invertebrates of California. Stanford University Press, Stanford, CA. 8. CHRISTOFFERSEN, M. L. 1987. Phylogenetic relationships of hippolytid genera with an assignment of new families for the Crangonoidea and Alpheoidea (Crustacea, Decapoda, Caridea). Cladistics. 3:348- 362. Hiebert, T.C. 2015. Heptacarpus paludicola. 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. 9. GUERAO, G., and J. A. CUESTA. 2014. Caridea, p. 250-255. In: Atlas of crustacean larvae. J. W. Margtin, J. Olesen, and J. T. Høeg (eds.). Johns Hopkins University Press, Baltimore. 10. KOZLOFF, E. N. 1993. Seashore life of the northern Pacific coast: an illustrated guide to northern California, Oregon, Washington, and British Columbia. University of Washington Press, Seattle. 11. KURIS, A. M., P. S. SADEGHIAN, J. T. CARLTON, and E. CAMPOS. 2007. Decapoda, p. 632-656. In: The Light and Smith manual: intertidal invertebrates from central California to Oregon. J. T. Carlton (ed.). University of California Press, Berkeley, CA. 12. PULS, A. L. 2001. Arthropoda: Decapoda, p. 179-250. In: Identification guide to larval marine invertebrates of the Pacific Northwest. A. Shanks (ed.). Oregon State University Press, Corvallis, OR. 13. RATHBUN, M. J. 1904. Decapod crustaceans of the northwest coast of North America. Harriman Alaska Expedition. x:1-210. 14. RICKETTS, E. F., and J. CALVIN. 1971. Between Pacific tides. Stanford University Press, Stanford, California. 15. RUPPERT, E. E., R. S. FOX, and R. D. BARNES. 2004. Invertebrate zoology: a functional evolutionary approach. Thomson Brooks/Cole, Belmont, CA. 16. SCHMITT, W. L. 1921. The marine decapod crustacea of California. University of California Publications in Zoology. 23:1-470. 17. STRATHMANN, M. F. 1987. Phylum or Subphylum Crustacea Class Malacostraca Order Decapoda, Caridea, p. 432-440. In: Reproduction and development of marine invertebrates of the northern Pacific coast. M. F. Strathmann (ed.). University of Washington Press, Seattle. 18. WICKSTEN, M. K. 1986. A new species of Heptacarpus from California, USA with a re-description of Heptacarpus palpator (Owen) (Caridea: Hippolytidae). Bulletin Southern California Academy of Sciences. 85:46-55. 19. —. 2011. Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces. http://escholarship.org/uc/it em/7sk9t2dz. Scripps Institution of Oceanography, UC San Diego, San Diego, CA.