Pooredoce garyi, Bruce, 2009

Bruce, Niel L., 2009, A new genus and new species of Sphaeromatidae (Crustacea: Isopoda) from the Great Barrier Reef, Australia, Memoirs of Museum Victoria 66 (1), pp. 35-42 : 37-40

Pooredoce garyi sp. nov.

Figures 1–4

Material examined. Holotype, (4.1 mm), North Point , Lizard Island, 14.64553°S, 145.45335°E, 12 April 2008, from dead coral heads, 1.0– 1.5 m, CReefs stn CGLI 20 A, coll. N.L. Bruce, CReefs (MTQ– QM W30539 ).

Paratypes, (3.0 mm, immature), (non-ovig. 3.2, 3.0, 2.9 mm), juveniles (2.7, 2.5, 2.4, 2.4, 2.3 mm), same data as holotype (MTQ– QM W30540 ) .

Additional material. (3.3 mm), (non-ovig. 2.9 mm), manca (1.9 mm), Hicks Reef, 14.44803°S, 145.49920°E, 21 February 2009, outer reef, dead coral heads on reef edge, 5.0–7.0 m, CReefs stn LIZ09-16E, coll. N. Bruce & M. Błażewicz-Paszkowycz. (MTQ– QM W31261 ) .

Description of male. Body 1.8 times as long as greatest width, lateral margins subparallel, widest at pereonites 3–6; posterior dorsal raised transverse ridges surfaces granular, setose. Cephalon anterior margin without transverse ridges. Pereonite 1 about 1.2 times as long as pereonite 2; pereonites 2–6 subequal in length, pereonite 7 slightly shorter than 6.

Antennule peduncle article 1 1.7 times as long as wide, about 2.1 times as long as article 2; article 3 about half as long as article 1, 2.8 times as long as wide, 1.4 times as long as article 2; flagellum 9-articled, about 2.9 times as long article 3. Antenna peduncle article 1 short, articles 2 and 3 subequal in length, article 3 about 0.8 times as long as article 4; articles 4 0.7 as long as article 5; flagellum about 0.8 times as long as peduncle, extending to middle of margin of pereonite 1, with 9 articles.

Epistome anteriorly narrowly rounded, lateral margins with medial constriction; indistinct transverse ridge of nodules present. Left mandible incisor with 3 cusps, lacinia mobilis with 3 cusps, spine row of 3 curved, serrate spines; right mandible incisor with 3 cusps, spine row of 5 broad-based distally serrate spines; molar process round, crushing surface strongly ridged; palp article 1 1.2 as long as article 2 subequal, article 2 distolateral margin with 4 biserrate setae; article 3 with 8 biserrate setae, terminal seta being longest. Maxillule mesial lobe with 2 long, strongly CP, 2 long fringed and 2 short simple RS; lateral lobe with 10 broad-based, serrate RS and 1 curved, slender RS on gnathal surface, twelfth prominently pectinate seta set between these. Maxilla lateral lobe and middle lobe with 6 and 7 curved, pectinate RS respectively, mesial lobe with about 14 serrate and biserrate RS, proximal seta longest. Maxilliped endite lateral margin strongly convex, distal margin sub-truncate, with 8 sinuate CP RS, 1 blunt simple RS at sublateral angle, distomesial margin with 2 CP RS and single coupling hook; palp articles 2–5 with about 8, 8, 10 and 12 terminal setae respectively.

Pereopod 1 without setulose fringe on inferior margins; basis about 2.7 times as long as greatest width, approximately 2.3 as long as propodus; ischium 0.6 times as long as basis, 1.8 times as long as greatest width, superior margin with 2, sinuate, acute RS; merus about 0.5 times as long as ischium, about 1.2 times as long as greatest width, superior distal angle with 2 acute RS, inferior margin with 3 blunt RS distal-most being longest; carpus 0.8 times as long as wide, inferior margin with 2 RS, one blunt one acute; propodus 1.7 times as long as greatest width, 0.7 as long as ischium, inferior margin with 3 RS, 3 submarginal setae; dactylus 0.8 times as long as propodus, inferior margin with few simple scales. Pereopod 2 basis 2.7 times as long as greatest width, inferodistal angle with single long simple seta; ischium 0.8 times as long as basis, 2.5 times as long as greatest width, superior margin with 2 acute RS, distal inferior margin with 2 short acute RS; merus 0.5 as long as ischium, superior distal angle with 2 RS, inferior margin with 2 blunt RS; carpus 0.7 as long as merus, 1.2 times as long as wide, anterodistal angle with 1 RS, inferior margin with 2 blunt RS; propodus 0.6 times as long as ischium, 2.3 times as long as wide, superior distal angle with ~4 long simple seta and 1 sensory seta, inferior margin 1 acute RS and 2 submarginal setae; dactylus 0.6 as long as propodus, inferior margin distally with scales. Pereopod 3 similar to pereopod 2. Pereopods 5–7 similar. Pereopod 7 basis 3.2 times as long as greatest width, inferodistal angle with 1 long simple seta; ischium 0.9 times as long as basis, 3.2 times as long as greatest width, superior margin with 4 sinuate, acute RS; merus 0.4 times as long as ischium, superior distal angle with 2 acute RS, inferior margin with 4 RS (3 acute, proximal RS blunt); carpus 0.8 times as long as merus, anterodistal margin with 5 acute serrate and biserrate RS, inferior distal angle with 4 RS, inferior margin with 1 RS; propodus 0.6 times as long as ischium, 2.9 times as long as wide, inferior margin with 2 RS, superior distal angle with 1 palmate seta and 3 simple setae; dactylus 0.5 as long as propodus.

Penes mutually adjacent, lateral margin distally convex, mesial margin weakly sinuate; approximately 3 times as long as basal width.

Pleopod 1 exopod and endopod with c. 32 and 20 PMS respectively, exopod proximolateral RS present; endopod and exopod subequal in length, endopod 1.4 times as long as greatest width, distal margin narrowly rounded. Pleopod 2 exopod and endopod with c. 32 and 22 PMS respectively; appendix masculin a 8.7 times as long as basal width, apically narrowly rounded. Pleopod 3 exopod and endopod with c. 27 and 9 PMS respectively; exopod transverse suture entire. Pleopod 4 exopod lateral margin proximally with 4 evenly spaced fine simple setae; endopod with single distal seta. Pleopod 5 endopod distal margin truncate.

Uropod (in situ) exopod about 0.5 as long as endopod, 3.1 times as long as greatest width, extending to endopod apex, margins converging to acute, finely bifid apex; endopod about 2.8 as long wide, curving medially, apex acute, curving dorsally; both with fine nodules and heavily setose.

Female. No ovigerous females present. Uropod endopod 2.8 as long as wide, posteriorly truncate; exopod 0.6 as long as endopod, 2.6 as long as wide, apically bifid, lateral side of apical division largest. Non-ovigerous females otherwise characterized by the generic characters.

Size. Adult males 3.3–4.1 mm; adult females 2.9–3.2 mm; juveniles 2.3–2.7 mm.

Remarks. Males can be identified by the generic characters, principally the unique pleotelson morphology in conjunction with the uropods. The females are rather similar to females of several other genera, notably Cilicaea and Paracilicaea , and are best identified by the very setose dorsal surfaces, the pleotelson posterior margin median notch appearing somewhat truncate and dorsal part being produced and overriding the lateral notches. Females of Oxinasphaera lack a distinct pleotelson notch.

Distribution. Northern Great Barrier Reef; on exposed reef edges from mid-shelf at Lizard Island and the outer reef front at Hicks Reef, intertidal to at least 7 m.

Figures

Figure 1. Pooredoce garyi sp. nov. A–H holotype, remainder 3.3 mm paratype. A, lateral view; B, dorsal view; C, epistome; D, pleon and pleotelson, posterior view; E, pleotelson, dorsal view; F, pleotelson, ventral view; G, pleotelson sinuses, ventral view; H, uropod; I, female, dorsal view; J, pleon and pleotelson, lateral view; K, pleotelson, ventral view; L, female pleotelson sinus, posterior view.

Figure 2. Pooredoce garyi sp. nov. A, B holotype, remainder 3.0 mm paratype. A, antennule; B, antenna; C, left mandible; D, right mandible incisor; E, maxillule; F, maxilla; G. maxilliped; H, maxilla mesial lobe.

Figure 3. Pooredoce garyi sp. nov. Holotype. A–C, pereopods 1, 2 and 7 respectively; D, propodus and dactylus, pereopod 1; E, RS from inferodistal margin of carpus, pereopod 7.

Figure 4. Pooredoce garyi sp. nov. Holotype except E, 3.0 mm paratype. A–E, pleopods 1–5 respectively; F, penes.