Bruceopsis projectus Anker, 2010, sp. nov.
Creators: name: Anker, Arthur
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Alpheidae
Bruceopsis
Bruceopsis projectus

description: Bruceopsis projectus sp. nov.
(Figs. 1 A,B, 2–5)
Type material. Holotype: ovigerous female (cl 6.2 mm, tl 16.9 mm, dissected), FLMNH UF Arthropoda 10948, Mariana Islands, Guam, Agat Bay north of Alutom Islet, under rocks, 3-7 m, coll. H.T. Conley, 2000- 2001 (exact date unknown).
Description. Body not particularly slender, moderately compressed (Figs. 1 A –B). Carapace smooth, sparsely covered with stubby setae (Figs. 1 B, 2B); cardiac notch well developed (Fig. 1 B). Frontal margin with rostrum and orbital teeth; rostrum well developed, thickened, acuminate, longer than wide, tip reaching slightly beyond distal margin of first segment of antennular peduncle, with marked lateral ridge and convex lateral margin; orbital teeth strong, sharp, anteriorly directed, reaching 0.4 length of rostrum (Figs. 2 A –B). Pterygostomial margin rounded, not projecting (Fig. 2 B). Eyes partly covered by orbital hoods, anterior-most portion of cornea visible in dorsal view; cornea well pigmented, anteromesial surface with small sharp dorsal process (Figs. 2 A –B). Epistomial sclerites with sharp ventrally directed teeth (Fig. 3 L).
Abdomen with second pleomere conspicuously enlarged in female (Fig. 1 B); third pleomere with small acute point at posteroventral angle (visible in Fig. 1 B); fourth pleomere rounded, with small inconspicuous blunt projection at posteroventral angle; fifth pleomere with posteroventral region angular, not projecting; sixth abdominal somite not elongate, with unusually elongate, laterally projecting articulated plate at posteroventral angle (Figs. 1 B, 2E–G); posterolateral angle sharply produced (Fig. 2 E). Telson subrectangular, tapering posteriorly, about 1.8 times as long as wide at base; dorsal surface with two pairs of strong dorsal spines inserted at about half-length and 0.75 length of telson, respectively (Fig. 2 I); posterior margin slightly convex, with two pairs of posterolateral spines, lateral much shorter and slenderer than mesial; margin between posterolateral spines with 10 plumose setae (Fig. 2 J); anal tubercles absent.
Antennular peduncle robust; first segment with strong acuminate stylocerite, reaching or nearly reaching distal margin of second segment (Figs. 2 A –B); mesioventral carina with strong compressed tooth (Fig. 2 C); second segment subquadrate in dorsal view, much shorter than first; third segment about the same length as second; lateral flagellum thicker than mesial, bifurcating at fifth segment, secondary ramus well developed, elongate, without visible segmentation; tufts of aesthetascs present on ventral margin from third segment to tip of secondary ramus (Fig. 2 D). Antenna with stout basicerite, armed with anteriorly projecting, sharp distolateral tooth (Fig. 2 B); carpocerite short, moderately stout, not exceeding scaphocerite; scaphocerite reaching far beyond distal end of antennular peduncle, ovate, with strong, acute distolateral tooth; blade broad, with strongly convex anterior margin, slightly exceeding distolateral tooth (Fig. 2 A); flagellum narrower than lateral antennular flagellum, but stouter than mesial antennular flagellum.
Mouthparts (Figs. 3 A –G) typical for family. Mandible with bisegmented palp; incisor process well developed, with nine teeth, centrally situated teeth stronger (Fig. 3 A); molar process well developed, with distal ridge, protuberances and dense rows of stiff setae (Fig. 3 A, B). Maxillule with bilobed palp, lower lobe with moderately stout seta; upper lobe with two slender setae (Fig. 3 C). Maxilla with small, unsegmented palp (endopod); basal endite with deep cleft; scaphognathite rather narrow (Fig. 3 D). First maxilliped (Fig. 3 E) with palp (endopod) bearing at least two segments, distally fringed with long plumose setae; caridean lobe of exopod poorly developed (Fig. 3 F); epipod bilobed. Second maxilliped with moderately elongate epipod (Fig. 3 G).
Third maxilliped pediform, slender (Fig. 3 H); coxa with small lateral plate adjacent to mastigobranch, furnished with setae (Figs. 3 J, K); exopod well developed, almost reaching distal end of antepenultimate segment, with long flexible setae basally; antepenultimate segment slender, compressed, somewhat depressed on ventral margin, setose; penultimate segment about 0.35 length of antepenultimate segment, more than three times as long as wide; ultimate segment elongate, tapering distally with rows of serrate setae, ending in subacute corneous tip, with two stout subdistal spines (Fig. 3 I); arthrobranch small.
First pereiopods (chelipeds) unequal in size, asymmetrical in shape (Fg. 1B). Major cheliped moderately enlarged compared to other alpheid genera (Fig. 4); coxa with rounded dorsal protuberance near basis (Figs. 4 G–H), ischium small, unarmed; merus relatively slender, about five times as long as wide, unarmed, ventral margin depressed (Fig. 4 D), mesioventral margin distally with comb-like row of setae (Fig 4 F); carpus short, cup-shaped, slightly constricted dorsally, mesially with comb-like row of setae (Fig. 4 F); chela with palm smooth, slightly compressed, ovoid in cross-section; fingers about as long as palm, slightly curved ventrally in lateral view (Fig. 4 A); dactylus somewhat expanded laterally and shallowly excavated ventrally (Figs. 4 A –C), cutting edge with four rounded, regularly spaced teeth in distal half and one minute subdistal tooth near tip; pollex not particularly modified, cutting edge with seven rounded or subtriangular, regularly spaced teeth and two smaller subdistal teeth near tip (Fig. 4 E); both dactylus and pollex furnished with elongate setae (Figs. 4 B, E). Minor cheliped shorter than major cheliped, minor chela volume around 30–40% of that of major chela (Fig. 1, cf. Figs. 4 A, 5 A); coxa with rounded dorsal protuberance near basis (Fig. 5 A); ischium and merus similar to those of major chela except for size; merus with row of comb-like setae distomesially (Figs. 5 B–D); carpus more elongate compared to that of major cheliped, vase-shaped, slightly constricted distodorsally, mesially with comb-like row of setae (Figs. 5 B–D); minor chela with palm shorter than palm of major chela, smooth, slightly compressed, ovoid in cross-section; fingers somewhat shorter than palm, not curved ventrally; dactylus not especially modified, not expanded and not excavated ventrally, cutting edge with some rugosities rather than distinct teeth; pollex with cutting edge bearing four small rounded, regularly spaced teeth on proximal 0.65 of its length (Fig. 5 C); both dactylus and pollex furnished with fewer elongate setae or tufts of setae compared to major chela (cf. Fig. 5 C and 4E).
Second pereiopod not elongate, slender, ischium slightly longer than merus; carpus five segmented, with ratio approximately equal to 3:1:1:1:1.7; chela longer than most-distal carpal segment, simple (Fig; 5E). Third pereiopod slender; ischium with two spines in sockets; merus almost seven times as long as wide, unarmed; carpus 0.6 times length of merus, distoventral margin with one stiff seta; propodus longer than merus, ventral margin with five slender spines in addition to distal spine adjacent to dactylus (Fig. 5 F); dactylus slender, conical, slightly curved, simple, dorsal margin with one slight notch distal to dactylus mid-length and one more conspicuous notch (almost forming a small tooth) at 0.65 length of dactylus (Fig. 5 G). Fourth pereiopod generally very similar to third. Fifth pereiopod with unarmed ischium; merus and carpus similar to those of third pereiopod, carpus without stiff seta distoventrally; propodus with at least seven spinules on ventral margin and ventrolateral brush consisting of about 11 short setal rows (Fig. 5 H, I); dactylus generally similar to that of third pereiopod, with two small notches on dorsal margin (Fig. 5 I).
First pleopod of female biramous, endopod about 0.3 length of exopod, very slender, margins fringed with setae. Second pleopod of female biramous; endopod with appendix interna. Uropod with ovate endopod, exopod ovate mesially, with straight lateral margin; protopod with strong sharp tooth on lateral lobe; diaeresis with large subtriangular tooth adjacent to distolateral tooth; distolateral spine strong, somewhat elongate (Fig. 2 H).
Gill/exopod formula as given for genus. Colour pattern unknown.
Size. Holotype, ovigerous female, cl 6.2 mm, tl 16.9 mm; egg diameter approximately 0.5 × 0.8 mm.
Etymology. The specific name projectus (projecting or prominent in Latin) refers to the peculiarly elongate and projecting articulated plate, a feature not observed in any other alpheid shrimp.
Ecology. The only available field notes indicate that the shrimp was collected “under rocks”, at a depth of 3–7 m, possibly on a fore reef or reef slope. However, the typical collecting style of H. T. Conley was to search for cryptic invertebrates on the extensive rubble beds of Guam, excavating piles of dead corals by hand (Dennis & Aldhous 2004), often reaching 1 m or deeper under the bed surface. This method resulted in the finding of several hitherto undescribed genera and species of crabs (e.g. Ng & Takeda 2003; Ng & Ng 2003), a ghost shrimp (Kensley 2001), and an unusual new species of shrimp from the genus Lysmata Risso, 1816 (Anker, unpubl.).
Distribution. Presently known only from the type locality, Agat Bay, north of Alutom Islet, Guam, Mariana Islands.
Remarks. See under the following species.
description: Published as part of Anker, Arthur, 2010, Description of a new genus and two new species of alpheid shrimps from Guam (Crustacea, Decapoda) *, pp. 389-404 in Zootaxa 2372 on pages 392-399, DOI: 10.5281/zenodo.275825