Margueritta sandyi, 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 : 346-348

publication ID	https://doi.org/ 10.24199/j.mmv.2003.60.28
persistent identifier	https://treatment.plazi.org/id/038D87F1-FFF4-FFD1-FF72-FEAC4400F958
treatment provided by	Felipe
scientific name	Margueritta sandyi
status	sp. nov.

Treatment

Margueritta sandyi View in CoL sp. nov.

Figures 28–30 View Figure 28 View Figure 29 View Figure 30

Material examined. Holotype. Female (3.2 mm, ovigerous), western side of Carnac I., off Fremantle, WA, 18 Dec 1971, 4–7 m, on algae, W.F. Ponder ( AM P50939 ).

Paratypes. Female (2.9 mm, non-ovigerous), manca (1.5 mm), North Lumps, 2 km off Mullaloo, WA, 31°47.30´S, 115°42.80´E, 2 May 1986, 8 m, red algal turf adjacent to reef, G.C.B. Poore and H.M. Lew Ton ( NMV J26053 View Materials ) GoogleMaps .

Holotype of Margueritta sylviae Bruce, 1993 ( AM P41021 ).

Description of female. Body about 1.7 times as long as greatest width, ovate, widest at pereonites 2 and 3; dorsal surfaces smooth, with irregular series of low bosses these provided with scattered setae. Cephalon anterior margin anteriorly projecting over frons, medially indented; without transverse ridge, ventral rostral process weakly developed. Pereonites 1 about 1.6 times as long as head in length in lateral view, about 1.8 as long as pereonite 2, with 2 clusters of low sublateral bosses; pereonites 2–7 of approximately equal length; pereonites 2, 3 and 5 with submarginal irregular transverse row of low bosses; pereonite 4 with one large median boss and single boss at each lateral margin; pereonites 6 and 7 each with two submedian bosses, pereonite 6 with 2 additional low submarginal bosses; coxae with sutures, ventrally directed, each with dorsal boss. Pleonite 1 entire; pleon otherwise without evident sutures, posterior margin indicated short lateral suture. Pleotelson with prominent anteriorly positioned median boss; posterior margin with distinctly produced ventrally open tube extending beyond posterior of uropodal rami.

Antennule peduncle article 1 about 3.3 times as long as distal width, anterior margin with 3 stout simples setae and 1 palmate seta; peduncle article 2 about half as long as article 1, 1.7 times as long as wide, anterodistal margin with 1 long and 1 short simple setae and 3 palmate sensory setae; article 3 about 0.7 as long as article 2, weakly offset on posterior margin of article 2; flagellum 4-articled, extending to pereonite 1, about 2.8 times as long article 3. Antenna peduncle articles 1–3 short, combined lengths 1.5 times as long as article 5; article 4 about 0.8 as long as article 5, both articles 4 and 5 with inferior margins convex; flagellum about equal in length to peduncle, extending to anterior margin of pereonite 2, with 8 articles.

Epistome smooth, narrow, laterally encompassing labrum, not anteriorly produced. Mandible as for the genus. Maxillule mesial lobe with 2 long, weakly pectinate setae and 2 shorter simple seta, lateral lobe with 10 peripheral RS on gnathal surface. Maxilla lateral lobe and middle lobe each with 2 and 3 curved RS respectively, mesial lobe with 6 setae, variously circumplumose, mesial-most seta only being acute, remainder terminally rounded. Maxilliped endite extending to palp article 5, distal margin with 1 conical RS, 3 rounded RS, 2 cactus RS and 3 slender CP RS; palp articles 2–5 with about 6, 12, 10 and 10 setae respectively.

Pereopod 1 basis about 2.4 times as long as greatest width, 1.6 times as long as propodus; inferodistal angle with 1 long simple setae; ischium 0.9 times as long as basis, 2.4 times as long as greatest width, margins with scale-setae more abundant on inferior margin; merus about 0.2 as long as ischium, 1.8 times as long as greatest width, inferior margin with sparse scale-setae and single long simple seta; carpus (inferior margin) 0.6 as long as merus, 0.4 as long as wide, with single simple seta; propodus 0.7 times as long as ischium, twice as long as greatest width inferior margin with single distal simple seta; dactylus about o.8 times as long as propodus, inferior margin with prominent serrate cuticular scales; unguis strongly recurved, secondary unguis recurved with 2 basal cusps. Pereopods 2 and 3 similar to pereopod 1, but with more and longer setae. Pereopods 5 and 6 similar, shorter than pereopods 1 and 2. Pereopod 7 slightly longer than pereopods 2–6, otherwise generally similar.

Pleopod 1 exopod and endopod with 8 and 9 PMS respectively, both rami distally narrowly rounded; endopod 0.6 as long as exopod, 2.5 times as long as greatest width, proximolateral margin weakly concave. Pleopod 2 exopod and endopod with c. 18 and 15 PMS respectively, those of distal margin of endopod submarginal; endopod twice as long as exopod. Pleopod 3 exopod and endopod with c. 17 and 14 PMS respectively. Pleopods 4 and 5 damaged, examined in situ, similar to that of the type species. Uropods not dissected and not examined in detail; rami flat, distally rounded, not extending to distal margin of pleotelson.

Male. Unknown.

Etymology. For Dr A.J. (Sandy) Bruce in recognition of his contribution to knowledge of the Crustacea, and to Caridea of the tropical Indo-Pacific and Australia in particular.

Distribution. Carnac I. and off Mullaloo, southern WA; on algae; 4– 8 m.

Remarks. The numerous small dorsal bosses and the prominent median bosses on pereonite 4 and the pleotelson separate this species from its congener, Margueritta sylviae . Additional conspicuous points of differences are that in M. sandyi the body shape is narrower, the body itself is more strongly vaulted and the pleotelson extends posterior to the uropodal rami.