Pedinura flindersia, Bruce, 2003

Bruce, N. L., 2003, New genera and species of sphaeromatid isopod crustaceans from Australian marine coastal waters, Memoirs of Museum Victoria 60 (2), pp. 309-369 : 356-363

Pedinura flindersia sp. nov.

Figures 35–39

Material examined. Holotype. Male (3.8 mm), “The Hotspot” reef, 5 n. miles W of north end of Flinders I., SA, 33°40.50´S, 134°22´E, 19 Apr 1985, 17 m, assorted red algae, S. Shepherd ( NMV J39728 ).

Paratypes. Vic. 3 females (immature 2.0, 2.2, 2.3 mm), 2 mancas (1.1, 1.2 mm), Whalers Point Lighthouse , Portland, 38°20.5´S, 141°37.5´E, 1 May 1988, 10 m, brown algae from boulder bottom, R. T . Springthorpe and P.B. Berents ( AM P50944 ). Male (5.0 mm), 38°40´S, 145°35´E, 6 Mar 1982, 0 m, rocky, G.C.B. Poore ( NMV J26380 ). Female (4.2 mm), 2 mancas (1.5, 2.5 mm), 500 m offshore, 1 km E of Harmers Haven, 38°34´S, 145°40´E, 6 Mar 1982, 11 m, rocky, C. Larsen and G. Barber ( NMV J26377 ). Male (4.1 mm), female (3.0 mm), 300 m offshore, E of Harmers Haven, 38°34´S, 145°40´E, 6 Mar 1982, 6 m, rocky, R . S. Wilson and C. Larsen ( NMV J26381 ). Male (5.5. mm), female (3.5 mm), 50 m offshore, E side of South Point, Twin Reefs , 38°41´S, 145°39´E, 4 Mar 1982, 11 m, rocky, C. Larsen, G. Barber and R . S. Wilson ( NMV J26383 ). Male (4.2 mm), The Oaks, Bunurong Coast, 38°40´S, 145°38´E, 5 Mar 1982, rock, G.C.B. Poore ( NMV J26375 ). Male (3.1 mm), Eagles Nest , Venus Bay , 38°40´S, 145°40´E, 5 Mar 1982, rock, G.C.B. Poore ( NMV J26378 ). Female (5.2 mm), NW side of Henty Reef , Mounts Bay , 38°47.0´S, 143°40.5´E, 3 May 1988, 18 m, red algae on boulder, R. T . Springthorpe and P.B. Berents ( AM P50946 ). SA . 2 males (3.3 dissected, 3.4 mm), 6 females (ovigerous 3.7, 4.4, 5.0 dissected, non ovigerous 2.9, 3.0, 3.1 mm), immature (2.4, 2.6, 2.8, 3.0, 3.8 mm), mancas (1.7, 1.7, 1.8 mm), same data as holotype ( NMV J39721 ). 2 males (3.0, 3.2 mm), 2 females (3.4, 3.6 mm), Snapper Point, Beachport , 37°29.3´S, 139°59.6´E, 14 May 1990, 6.0 m, brown algae, on limestone reef, G.C.B. Poore ( NMV J26231 ). WA . Female (3.0 mm), Seven Mile Beach, N of Dongara, 29°12´S, 114°53´E, 24 Apr 1986, 1 m, Amphibolus epiphytes, G.C.B. Poore and H.M. Lew Ton ( NMV J26173 ). Female (4.1 mm), Cliff Head, S of Dongara, 29°32´S, 114°59´E, 22 Apr 1986, 1 m, red algae on limestone, G.C.B. Poore and H.M. Lew Ton ( NMV J26158 ). Female (3.9 mm), off jetty, Green I., Rottnest I., 32°01´S, 115°30´E, 21 Dec 1983, 1 m, mixed algal turf on rock, R. T . Springthorpe ( AM P50943 ) .

Other material, unmeasured. Vic. Bay of Islands, 38°35.0´S, 142°49.5´E, 2.5 m, red algae (AM P50945). Portland, 38°24´S, 141°40.5´E, 23m, Herdmania momus with encrusting sponge and red algae (AM P50947). SA. Topgallant I., Investigator Group, 33°43´S, 133°36.60´E, 20 m, on Cystophora and Plocamium (NMV J39730). “The Hotspot” reef, N end of Flinders I., 33°40.50´S, 134°22´E, 12 m, assorted algae (NMV J39706); 21 m, red algae (NMV J39722). 7, 2.3 n. miles W of Tiparra Light, Tiparra Reef, Tiparra Bay, 15 Mar 1985, 10 m, red algae (NMV J39727). WA. Port Denison Beach, Dongara, 5 m, red algae, mainly Laurencia (NMV J39704).

Description of male. Body about 3.2 times as long as greatest width, lateral margins subparallel, pereonites of subequal width, pereonite 4 marginally widest; dorsal surfaces smooth, unornamented. Head anterior margin without transverse ridge, rostral process not visible in dorsal view. Head and pereonites 1 subequal in length in dorsal view, pereonites 1>2=3<4=5>6>7. Pleotelson posterior margin smoothly rounded.

Antennule peduncle article 1 1.4 times as long as proximal width, about 2.6 times as long as article 2; article 2 flattened, about as long as wide, anterior margin with single small seta, posterodistal angle with 2 small setae; article 3 about half as long as article 2; flagellum 4-articled, extending to anterior of pereonite 1, about 0.4 times as long article 3. Antenna peduncle articles 1 and 2 about as long as combined lengths of article 3 and 4; article 4 about as long as article 5, about 1.3 times as long as wide; flagellum about equal in length to peduncle, extending to anterior margin of pereonite 2, with 6 articles.

Epistome smooth, narrow, laterally encompassing labrum, anteriorly forming distinct point. Mandible incisor with 3 cusps; lacinia mobilis absent; spine row of 3 serrate curved spines, on right mandible with additional broad-based multidigitate spine; molar process appearing largely smooth, without serrate margins or ridged surfaces; palp article 1 longest, without setae; article 2 with 3 biserrate setae, article 3 with 4 biserrate setae, terminal seta being largest. Maxillule mesial lobe with 2 long and 1 shorter weakly CP and 1 short simple seta; lateral lobe with 9 peripheral simple RS on gnathal surface, eleventh seta set between these. Maxilla lateral lobe and middle lobe each with 4 curved flat simple RS respectively, mesial lobe with about (not clearly observed) 6 RS, variously serrate. Maxilliped endite extending about half way along palp article 3, distal margin with 1 conical RS, 3 rounded RS, 1 cactus RS and laterally with 2–3 slender CP RS; palp articles 2–5 with about 4, 9, 8 and 11 setae respectively.

Pereopod 1 basis about 1.6 times as long as greatest width, about 1.1 times long as propodus; ischium 0.6 times as long as basis, 1.8 times as long as greatest width, inferior surfaces with abundant microtrichs; merus about 0.7 times as long as ischium, 0.7 times as long as greatest width; carpus (inferior margin) 0.7 as long as merus, 0.8 times as long as wide; propodus 1.5 times as long as ischium, 1.9 times as long as greatest width, inferior margin with 2 biserrate RS, inferodistal margin with 2 biserrate RS and 2 short simple setae adjacent to base of dactylus; dactylus 0.4 times as long as propodus, unguis strongly recurved, inferior margin with few small cuticular scales, secondary unguis recurved with 2 basal cusps. Pereopod 2 with all articles slender; basis about 3.1 times as long as greatest width, about as long as propodus; ischium 0.8 times as long as basis, 2.5 times as long as greatest width, inferodistal angel with single seta; merus about 0.7 times as long as ischium, 1.7 times as long as greatest width, superior distal margin strongly convex; carpus 1.7 as long as merus, 4 times as long as wide; propodus 1.3 times as long as ischium, 5.3 times as long as greatest width; dactylus 0.4 times as long as propodus, unguis slender apically falcate, secondary unguis flat and strongly pectinate extending alongside unguI. Pereopod 3 similar to 2, but a little more robust. Pereopods 4–7 similar to pereopod 1, but carpus quadrate rather than subtriangular, propodus inferior margin without biserrate RS; all pereopods without trifid and biserrate setae. Pereopod 7 basis with proximal flange; carpus distal margin with single simple acute RS.

Penial processes separate, adjacent, about 1.7 times as long as basal width, quadrate in shape, distal margin weakly oblique, feebly indented.

Pleopod 1 exopod and endopod with c. 14 and 12 PMS respectively; rami of similar size, endopod 0.9 as long as exopod, 1.8 times as basal width, lateral margin converging slightly to rounded distal margin; exopod 2.0 time as long as greatest width, margins subparallel, distal margin broadly rounded. Pleopod 2 exopod and endopod with c. 18 and 12 PMS respectively, pleopod 2 endopod 1.2 times as long as exopod, 2.3 times as long as greatest width, lateral margin strongly recessed at insertion point of appendix masculina; appendix masculina attached about half way along mesial margin, lateral surface with abundant microtrichs, about 5.3 times as long as wide, 0.8 times as long as endopod, apex bluntly rounded. Pleopod 3 exopod and endopod with c. 24 and 11 PMS respectively; both rami elongate, endopod very slightly (1.06) longer than exopod, slender, 2.9 times as long as greatest width, proximal lateral margin convex. Pleopod 4 both rami with prominent ridges, exopod lateral margin with fine setae, exopod suture incomplete. Pleopod 5 both rami with prominent ridges; exopod with 2 distal scale patches, and transverse absent. Uropod rami flattened, margins provided with mebrana cingula; exopod inserted into lateral margin at about one-third from posterior margin, 02 times as long as fused endopod, anterior margin convex, posterior weakly concave, distal margin narrowly rounded; endopod anterolateral margin straight, posterolateral part subtruncate, mesial margin weakly convex; broadly rounded, proximomesial cluster of 3 sensory setae.

Female. Anterior body outline includes conspicuously expanded antennule peduncular articles 1; rostral point evident in dorsal view; eyes smaller than in males. Antennule peduncle article 1 0.8 times as long as mesial width, about 2.6 times as long as article 2, anteriorly produced, plate-like; article 2 flattened, about as long as wide, anterior margin produced, anteromesial angle at right angles, forming continuous margin with peduncular article 1; article 3 anterior margin with small distinct anterior boss. Antenna as for the male.

Size. Males 3.1–5.5 mm, ovigerous females 3.7–5.0 mm, non-ovigerous females 2.9–5.2 mm; juvenile (sex indeterminate) 2.4–3.8 mm; mancas 1.1–2.5 mm.

Etymology. From the type locality; noun in apposition. Distribution. Vic. (Bunerong), SA, WA (Rottnest I., Seven Mile Beach, Dongara); intertidal to 21 m; mainly on red and brown algae, specifically on Cystophora , Laurencia and Plocamium .

Remarks. This species is distinguished by the posterior margin of the pleotelson being widely subtruncate and without a median indentation. Further distinguishing characters include the strongly expanded antennule peduncle articles 1 and 2, the anteriorly acute epistome not visible in dorsal view, robust pereopods and the uropod exopod being set distally on the endopod.

Figures

Figure 35. Pedinura flindersia sp. nov. A–D, holotype, remainder male paratype NMV J39721. A, dorsal view; B, lateral view; C, frons, ventral view; D, pleon and pleotelson, ventral view; E, antennule; F, antenna; G, maxilliped; H, left mandible; I, right mandible.

Figure 36. Pedinura flindersia sp. nov. All figs male paratype NMV J39721. A, maxilla; B, maxillule; C, pereopod 1; D, pereopod 1, dactylus; E, pereopod 2; F, pereopod 2, dactylus; G, pereopod 3; H, pereopod 6; I, pereopod 4; J, pereopod 7.

Figure 37. Pedinura flindersia sp. nov. All figs male paratype NMV J39721. A–E, pleopods 1–5; F, uropod; G, penes.

Figure 38. Pedinura flindersia sp. nov. All figs female paratype NMV J39721. A, dorsal view; B, lateral view; C, antennule; D, antenna.

Figure 39. Pedinura flindersia sp. nov. SEMs. Female, ‘The Hotspot’ reef, Flinders I., NMV J39722. A, anterior, lateral view; B, mandible; C, maxilliped, distal margin; D, pereopod 1 dactylus; E, pereopod 2, pectinate robust seta on propodus; F, uropod lateral margin; G, sensory setae, uropods.