Lebbeus mundus, Jensen, Gregory C., 2006

Jensen, Gregory C., 2006, Three new species of Lebbeus (Crustacea: Decapoda: Hippolytidae) from the Northeastern Pacific, Zootaxa 1383, pp. 23-43 : 30-34

Lebbeus mundus new species

Figs. 4 C, 5, 6

Type material: Holotype female, postorbital carapace length 7.2 mm, Willis Point, Vancouver Island, British Columbia, Canada (48.34.601°N, 123.29.319°W), suction gun, 9–12 m, 31 December 2005. G.C. Jensen, collector. National Museum of Natural History, Smithsonian Instititution, USNM 1092257. Allotype, 5.9 mm, Burrows Island, Anacortes, Washington, U.S.A. (48.29.251°N, 122.41.536°W), suction gun, 12 m, 20 November 2004, G.C. Jensen, collector, USNM 1092258. Paratypes collected same date and location as holotype deposited at the U.S. National Museum of Natural History (1 male, 2 females, USNM 1092259), California Academy of Sciences (2 males, 2 females, CASIZ 174051), Natural History Museum of Los Angeles County (2 males, 2 females, LACM CR 2005- 033.1), National Science Museum, Tokyo (1 male, 2 females, NSMT-Cr 16841), and British Columbia Provincial Museum (1 male, 1 female, RBCM 006-00055). Also female, Yeo Island Channel, Winchelsea Island, Strait of Georgia, British Columbia, Canada, 20 m, 26 October 1996, D. Gibbs, collector, RBCM 006-00057. Female, ovigerous, Barrie Reach, Gardner Canal, British Columbia, Canada (53.27.5°N, 128.10.5°W), <23m, 25 March 1976, P. Lambert and B. Cooke, collectors, RBCM 976-1034-20.

Other material examined: Two males, Pribilof Islands (56.36.79°N, 169.52.27°W), dredge, 85 m, 4 September 1983, G.C. Jensen, collector. Male, Pribilof Islands (57.06.37°N, 170.14.25°W), dredge, 27 m, 31 August 1983, G.C. Jensen, collector. Four specimens, off Larch Bay, Baranof Island, Alaska (56.12.1°N, 134.45.7°W), 134 m, 8 August 1983, A. Peden, collector, RBCM 983-01583-3. Male, Fitz Hugh Sound, Windsor Cove, mouth of Burke Channel, British Columbia (51.55.95°N, 127.52.95°W), 40–80 m, 21 August 1981, P. Lambert, collector, RBCM 981-00201-5.

Description: Integument smooth, fairly thick. Rostrum short, 0.37–0.5 carapace length, barely exceeding cornea; lateral face with longitudinal carina extending from base of supraorbital spine to 0.31–0.64 rostrum length. Carapace and rostrum ( Fig. 6 A) with 4 (occasionally 5) dorsal teeth, only 1–2 on carapace; females usually with dorsal carina extending 0.85–0.96 carapace length; carina not present in males. Rostrum usually lacking ventral teeth, rarely with a small subterminal tooth. Supraorbital spine very strong, with deep V-shaped notch ventrally; dorsal margin sometimes continuing as subdorsal carina in females only, 0.3–0.8 carapace length. Suborbital in the form of a strong, rounded lobe, antennal spine strong and sharp with deep notch ventrally; anterolateral margin strongly convex, pterygostomian spine distinct. Females with lateral carina, 0.67–0.88 carapace length.

Abdominal somites smooth except for dorsal, transverse furrow on the second abdominal somite. Pleura of abdominal somites 1–3 rounded; pleura of fourth and fifth abdominal somites with posteroventral spines. Telson ( Fig. 6 G) 1.3–1.6 length of sixth somite, with 4–5 pairs of dorsolateral spinules and three pairs of terminal spinules, lateral pair similar to dorsolateral series and middle pair with setules ( Fig. 6 H).

Eye somewhat pyriform; diameter 0.19–0.21 carapace length in females, 0.29–0.31 in males; cornea pigmented, ocellus present.

Basal article of antennular peduncle ( Fig. 6 B) with 3–4 distal, dorsal spines and a strong subdistal, ventromesial spine; stylocerite reaching to middle or middorsal end of second article of antennular peduncle. Second article with large dorsolateral spine on distal margin; third article with erect dorsal spine. Dorsolateral flagella of female 0.45–0.6 carapace length, with 14–20 thickened segments, distal portion slender, with 12–18 segments; entire flagella thickened and greatly elongated in males to 1.3–1.8 times carapace length, gradually tapering, with 38–50 segments. Ventromesial flagella longer than dorsolateral in females and subequal in males, with 30–45 segments.

Basicerite of antenna with rounded dorsal lobe and strong ventrolateral spine; carpocerite reaching to end of second article of antennular peduncle. Antennal scale about 2.5 times as long as wide and about 0.65 carapace length in females, about 3 times longer than wide and 0.78–0.8 carapace length in males; lateral margin straight, spine equal to or slightly exceeded by lamella. Antennal flagellum 4.6–7.4 times carapace length.

Mandible with two-segmented palp; distal article of palp densely setose, proximal article with a few sparse setae; incisors slender, with 4 distal teeth. Left molar large, subcylindrical, with large distal tooth and setal tufts. Right molar with 5–6 teeth on margin.

First maxilla with bilobed palp, lateral lobe tipped with a slender simple seta and a subterminal slender seta; mesial lobe with a thicker, plumose seta. Distal endite oval, densely armed with spinules and setae on mesial margin; proximal endite with long, stout setae.

Second maxilla with palp tipped by 2–3 long and one short seta. Basal endite bilobed, mesial margin densely setose. Coxal endite very small, with about 11 long, plumose setae. Scaphognathite densely fringed with plumose setae, longest anteriorly and anteromesially and along posterolateral margin. Anterior lobe of scaphognathite long, subrectangular; posterior lobe rounded.

First maxilliped palp densely setose, with two subequal articles. Caridean lobe well developed and fringed with long plumose setae. Exopod long, tipped with setae. Endites well-developed, densely setose on mesial margin. Epipod large, bilobed.

Second maxilliped with ultimate article densely setose on mesial margin; penultimate article with many long setae. Exopod well developed, tipped with long setae. Epipod somewhat oval, with small podobranch.

Third maxilliped with 10–11 apical and subapical corneous spinules; mesial margins of ultimate and penultimate articles densely setose. Distal margin of antepenultimate article with strong, subdorsal lateral spinule and smaller subventral spinule. Epipod present.

Pereopods 1–5 with pleurobranchs. First pereopods ( Fig. 6 C) equal, chelate, reaching to about the distal third of the antennal scale, sometimes to tip in small males. Dactyl 0.38–0.48 propodus length; propodus 3.5–3.7 times as long as wide and 0.37–0.47 carapace length. Antennal cleaning brushes on propodus and carpus. Carpus 1.2–2.1 times as long as wide; merus 2.3–4.0 times longer than wide and 1.4–1.8 times longer than carpus. Coxa with hooked epipod and setobranch.

Second pereopod equal, chelate, exceeding antennal scale by palm and most distal segment of carpus; dactyl 0.36–0.46 propodus length. Carpus with 7 segments, third from merus longest. Merus 0.51–0.62 carpus length. Coxa with hooked epipod and setobranch.

Third pereopod ( Fig. 6 D, E) dactyl with corneous, bifid tip preceded by 3–4 spinules on flexor margin. Propodus 12.2–14.4 times longer than wide in females and 8.9–13.4 times in males, with about 35 small spinules in two indistinct rows along flexor margin. Carpus 2.7–5.1 times as long as wide. Merus 5.6–10 times long as wide, with 3–5 lateral spinules increasing in size distally. Coxa with hooked epipod and setobranch.

Fourth and fifth pereopods similar to third but decreasing in size and lacking epipods; fourth with 2–5 meral spinules and setobranch on the coxa; fifth with 0–1 spinule and propodal grooming brush.

Endopod of first pleopod of female subequal to exopod. Endopod of first pleopod of male broad, flat, about two-thirds length of exopod and fused with appendix interna. Lateral margin with long plumose setae, mesial margin with curved plumose setae decreasing in length distally; distal third strongly tapered into fingerlike appendix interna with cincinnuli at the tip. Appendix masculina ( Fig. 6 F) stout, slightly less than half length of appendix interna, and tipped with 10–12 long spinules. Uropods subequal, reaching to tip of longest telson spinules.

Eggs oval, 1.16–1.25 X 0.83–1.0 mm. Ovigerous females ranged in size from 5.2–10.7 mm carapace length.

Color: Color pattern consistent but varying in intensity with habitat and sex, being brighter in females and in specimens collected from areas with more brightly colored encrusting organisms. Branchial region of carapace with irregular red spots; dorsal region with four short, narrow, evenly spaced electric blue bands. Abdomen with broad red bands separated by blue; telson and uropods reddish with no banding. Blue color tends to be faint or lacking in males. Walking legs reddish with widely spaced yellow bands; antennae orange, unbanded ( Fig. 4 C).

Distribution: Pribilof Islands, Alaska ( Jensen & Armstrong 1987, as L. schrencki ) to Octopus Hole, Hood Canal, Washington (47°26.792'N, 123°06.842'W), at depths of 9– 134 m.

Etymology: The Latin ‘mundus’ means clean, neat, or elegant, all terms appropriate for this shrimp given the cleaning behavior it exhibits (see Discussion) and its attractive markings. I recommend the common name ‘cleaner lebbeid’.

Figures

FIGURE 6. Lebbeus mundus, exuvium of male allotype. A, lateral view of carapace; B, antennular peduncle and antennal scale (dorsal view); C, chela of first pereopod, mesial view; D, third pereopod, lateral view; E, dactyl of third pereopod; F, appendix masculina and appendix interna; G, dorsal view of telson and uropods.

FIGURE 4. A, aquarium photo of Lebbeus eludus showing daytime coloration; B, in situ photo of L. eludus at night; C, in situ photograph of L. mundus; D, photograph of freshly-caught holotype of L. acudactylus. A – C by G. C. Jensen; D by K. P. Maslenikov.