Metaprotella guileri sp. nov.

(Figures 1 – 4)

Metaprotella excentrica. – Mayer 1903: 40. – Stebbing 1910: 652. – McCain and Steinberg 1970: 54 (in part). – Lowry and Stoddart 2003: 25.

Type material

Holotypeı maleı AM P.48733 ı 33 °51 ʹ 51 ʺ S 151°14 ʹ 28 ʺ Eı north-east corner of Clark Islandı Port Jacksonı New South Walesı red algae covered with thick sedimentı 7 m depthı 17 April 1996 ı coll. I. Takeuchi. Paratypesı 3 malesı 2 juvenilesı AM P.48734 ı 33 °51 ʹ 51 ʺ S 151° 14 ʹ 28 ʺ Eı north-east corner of Clark Islandı Port Jacksonı New South Walesı red algae covered with thick sedimentı 7 m depthı 17 April 1996 ı coll. I. Takeuchi.

Additional material examined

1 maleı AM G.931 ı 35 °03 ʹ S 150°44 ʹ Eı Jervis Bayı New South Walesı coll. T. Whitelegge; 1 maleı AM G. 2561ı 33°51 ʹ S 151°16 ʹ Eı Port Jacksonı New South Wales; 3 malesı AM G. 2567ı 33°51 ʹ S 151°16 ʹ Eı Port Jacksonı New South Wales; 3 malesı 1 mature femaleı AM P.3348 ı 33 °51 ʹ S 151° 16 ʹ Eı Port Jacksonı New South Wales; 2 mature femalesı AM P.24315 ı 33 °49 ʹ S 151°20 ʹ Eı east of North Headı Sydneyı New South Walesı Australian Museum Shelf Benthic Surveyı 20 February 1973; 4 mature femalesı AM P.47733 ı 33 °51 ʹ S 151°16 ʹ Eı Port Jacksonı New South Wales; 1 maleı AM P.68551 ı 35 °31 ʹ 39 ʺ S 150°24 ʹ 58 ʺ Eı north-west side of Brush Islandı north of Batemans Bayı New South Walesı hand collected on SCUBA alga Padina sp. ı 14 m depthı 9 February 2003 ı coll. P.B. Berentsı J. Euı A.J. Milları G.D.F. Wilsonı Hermon Slade Batemans Bay Expedition; 3 malesı 1 juvenile AM P.72649ı north-west side of Brush Islandı north of Batemans Bayı New South Walesı 35°31 ʹ 39 ʺ S 150°24 ʹ 58 ʺ Eı 9 February 2003 ı hand collected on SCUBA Sargassum sp. (alga) scattered low reefsı rocks and sandı 18.1 m depthı coll. P.B. Berentsı J. Eu. A.J. Milları G.D.F. Wilsonı Hermon Slade Batemans Bay Expedition; 2 malesı 2 juvenilesı AM P. 98926 ı 35 °44 ʹ 55 ʺ S 150°15 ʹ 27 ʺ Eı west side of North Tollgate Islandı Batemans Bayı New South Walesı 11 February 2002 ı hand collected on SCUBA alga Chondria succulenta ı 9 m depthı coll. P.B. Berentsı J. Euı A.J. Milları G.D.F. Wilsonı RV Baragulaı Hermon Slade Batemans Bay Expedition; 1 maleı AM P.98928 ı 35 °44 ʹ 47 ʺ S 150°15 ʹ 28 ʺ Eı north-west side of Tollgate Islandsı Batemans Bayı New South Walesı 28 October 2002 ı Aquatic hand collected on SCUBA macroalga Sporochnus radiciformis ı 12 m depthı coll. D.F. Wilsonı N. Yeeı P.B. Berentsı RV Connemaraı Hermon Slade Batemans Bay Expedition; 1 premature femaleı 2 juvenileı AM P.98929 ı 35 °44 ʹ 47 ʺ S 150°15 ʹ 28 ʺ Eı north-west side of Tollgate Islandsı Batemans Bayı New South Walesı 28 October 2002 ı Aquatic hand collected on SCUBA macroalga Sporochnus radiciformis ı 12 m depthı coll. D.F. Wilsonı N. Yeeı P.B. Berentsı RV Connemaraı Hermon Slade Batemans Bay Expedition; 1 mature femaleı AM P.98970 ı 33 °51 ʹ S 151°16 ʹ Eı Port Jacksonı New South Wales.

Type locality

Clark Islandı Port Jacksonı New South Walesı Australia.

Other localities

East of North Headı Sydneyı Jervis Bayı Brush Islandı and Batemans Bayı New South Walesı Australia.

Description

Holotype, male ı body length 8.82 mmı AM P.48733. Head 0.49 mm; pereonite 1ı 0.18 mm; pereonite 2ı 1.22 mm; pereonite 3ı 2.07 mm; pereonite 4ı 2.34 mm; pereonite 5ı 2.00 mm; pereonites 6 and 7 combinedı 0.53 mm.

Head/pereonite 1 fused (suture present) with paired small triangular dorsal projections; eye largeı distinctive. Antenna 1 slenderı 0.70 × body length; peduncle article 2 longest; peduncular article 3 straight; flagellum 0.70 × peduncular lengthı with 14 articlesı proximal article composed of 4 articles. Antenna 2 slender; 0.5 × antenna 1 length; peduncle setose; flagellum 0.25 × of peduncular lengthı with 2 articles.

Upper lip notchedı forming rounded quadrilateral projections. Mandible right incisor with 5 teeth; lacinia mobilis with 3 teethı with 2 bundled setal rows; palp 3-articulateı palp article 3 setal formula 1 – 19 – 1 – 1; molar well developed with flake; left incisor with 5 teeth; lacinia mobilis with 5 teethı 3 bundled setal rows; palp 3-articulate; palp article 3 setal formula 1 – 12 – 1 – 1; molar well developed. Lower lip finely setose on inner and outer lobes. Maxilla 1 outer plate with 7 stout apical setal-teeth; palp distal margin with 1 robust setaı 3 triangular projectionsı each with a slender or robust setaı 1 triangular projection without setaı and a row of 4 slender setae. Maxilla 2 inner plate trianguları with 8 setae; outer plate elongateı with 12 apical setae. Maxilliped basal endite (inner plate) subtrianguları with 2 small nodular setaeı with 4 setae near distal margin; ischial endite (outer plate) ovalı 2 × length of inner plateı inner margin blade-likeı with many fine setaeı with 1 seta on inner margin; palp article 2 setose on inner margin; palp article 3 expandedı with moderately dense distal setae; palp article 4 (dactylus) weakly falcate.

Pereon. Pereonite 2 with anterolateral bifurcated projectionı with small midlateral projectionı with paired anteriorly curved mid-dorsal projectionsı with simple dorsodistal projection. Pereonite 3 with subacute anterolateral projectionı with paired mid-dorsal projectionsı with simple dorsodistal projection. Pereonite 4 with small anterolateral projection. Pereonite 5 with small anterolateral projection. Pereonites 6 and 7 not articulated obliquely.

Gnathopod 1 merus and propodus setose; propodus subtrianguları propodus with 5 – 6 rows of submarginal setae on distal part (near anterior margin)ı palm begins 1/6 along posterior marginı minutely serrateı with 1 robust seta near corner of palmı dactylus slightly curved. Gnathopod 2 begins 1/5 (0.20) along anterior margin of corresponding pereonite; coxa vestigial; basis 0.6 × length of pereonite 2ı with small projection near distal margin; ischium with small distal projection; carpus 0.16 × propodus length; propodus subovateı largeı length 2 × widthı anterodistal margin slightly concave; palm proximal projection with 1 robust (grasping) setaı palm margin convexı smoothı with broad well-developed distal shelfı with two triangular projections distallyı with deepı narrow sinusı with midpalmar projection.

Gill 3 length about 1/4 of corresponding pereoniteı straight. Pereopod 3 with 1 articleı length 3 × widthı with 4 distal and 1 lateral setae. Gill 4 length about 1/6 of corresponding pereoniteı curved anteriorly. Pereopod 4 with 1 articleı length 2 × widthı with 5 distal and 2 lateral setae.

Pereopod 5 slender; basis shorter than propodus; carpus with 5 setae on anterior margin; propodus with 1 pair of robust setae from 2/5 on anterior marginı with 2 robust and 2 short setae along palm; dactylus curvedı not setose. Pereopod 6 more robust than pereopod 5. Pereopod 7 more robust than pereopod 6.

Pleon. Uropod 1 probably bi-articulate (suture unclear); peduncleı length about 2.5 × widthı with 6 – 8 lateral setae; ramus length about 0.3 × peduncular lengthı with 10 shorter setae. Telson (dorsal lobe) present.

Male, Body lengthı 15.47 mmı AM P.98928. Head 0.81 mm; pereonite 1ı 0.37 mm; pereonite 2ı 2.33 mm; pereonite 3ı 3.63 mm; pereonite 4ı 4.09 mm; pereonite 5ı 3.28 mm; pereonites 6 and 7 combinedı 0.96 mm. Head and pereonites slender. Head with paired small triangular dorsal projections; eye largeı distinctive. Antenna 1 slenderı 0.7 × body length; peduncle article 2 longest; peduncular article 3 straight; flagellum 0.45 × peduncular lengthı with 15 articlesı proximal article composed of 5 articles. Pereonite 2 with anterolateral bifurcated projectionı with 2 small midlateral projectionsı with paired anteriorly curved mid-dorsal projectionsı with round dorsodistal projection. Pereonite 3 with subacute anterolateral projectionı with round posterolateral projectionı with paired mid-dorsal projectionsı with round dorsodistal projection. Pereonite 4 with subacute anterolateral projectionı with small dorsolateral projection. Pereonite 5 with subacute anterolateral projection. Pereonites 6 and 7 not articulated obliquely. Gnathopod 2 begins 1/5 (0.20) along anterior margin of corresponding pereonite; coxa vestigial; basis about 0.8 × length of pereonite 2ı with distinct basal projectionı with triangular and round distal projections; propodus subovate.

Etymology

This species is named after Eric Guilerı marine biologist who studied caprellids in the 1950s at the University of Tasmania.

Remarks

The genus Metaprotella is one of the most dominant and widely distributed genera of the Caprellidae in the tropical region. Prior to the present studyı eleven species have been described from around the world (see McCain and Steinberg 1970; Larsen 1997; Guerra-García 2002 ı 2003; Lim and Takeuchi 2012; Momtazi and Sari 2013).

The present species was previously reported as Metaprotella excentrica Mayerı 1890 [sense lato] based on the specimens collected from Port Jacksonı New South Wales (see Mayer 1903 ı Stebbing 1910 ı McCain and Steinberg 1970. The type locality of M. excentrica was the Pamban Bridgeı Indiaı which is situated north of the Mannar between south-eastern India and northern Sri Lanka. Metaprotella excentrica [sensu lato] was also recorded from Ceylon (Sri Lanka) and Port Jacksonı New South Wales (see McCain and Steinberg 1970; Hutchings et al. 2013). Mayer (1890) first described this species based on the specimens from the type locality. Later Sivaprakasam (1977) described and figured a large male collected from Kilakkarai or Appa Island which is located on the Indian coast of the Gulf of Mannar. Guerra-García et al. (2010) also figured a mature male and female collected from Kasivari Island in the same Gulf of Mannar. All these figures for M. excentrica from India confirm the unique diagnosis for gnathopod 2ı which is the presence of three distal projections on the basis. Descriptions and/or figures of M. excentrica [sensu lato] from New South Wales have never been reported.

Metaprotella guileri sp. nov. from New South Wales differs from M. excentrica [sensu stricto] from India by: (1) the head possessing a pair of small triangular projectionsı M. excentrica [sensu stricto] projections of head are smallı but sharp; (2) pereonites 2 and 3 having anteriorly forwarded mid-dorsal triangular projectionsı while those projections of M. excentrica [sensu stricto] are sharp; (3) pereonite 2 lacking a pair of posterior dorsal projection which M. excentrica possesses; and (4) the basis of gnathopod 2 with one to two distal projectionsı while M. excentrica [sensu stricto] has three distal projections. Thusı we establish the new speciesı Metaprotella guileri. Considering the biogeographical distributionı previous records of M. excentrica [sensu lato] recorded from Port Jacksonı New South Wales (see McCain and Steinberg 1970; Hutchings et al. 2013) could be M. guileri sp. nov.

The specimens assigned as Metaprotella guileri sp. nov. were found in the old collection of the Australian Museum collected in Port Jackson and Jervis Bay and in materials collected in Port Jackson in 1996 and from Brush Island to Batemans Bay in the Hermon Slade Batemans Bay Expedition during 2003 to 2004. The male of materials collected in 1996 from Port Jackson (by ITı the senior author)ı where most of the old specimens were collectedı was selected as the holotypeı and the concurrently collected specimens were assigned as paratypes. While three mature females of the present species were found in the old collectionı these are not suitable for description and illustration due to being dried up or damaged. The largest male collected in the Hermon Slade Batemans Bay Expedition was also figured and described.

The present species shows an unique ontogenetic development of gnathopod 2 in larger males. Of the specimens studiedı 4 males longer than 12.80 mm in body length possess the distinct proximal projection and two distal round projections on the basis of gnathopod 2.