Metaprotella solitaria, Takeuchi & Lowry, 2019

Takeuchi, Ichiro & Lowry, James K., 2019, A taxonomic study on Orthoprotella and related genera (Crustacea: Amphipoda: Caprellidae) of New South Walesı Australia, Journal of Natural History 53 (17), pp. 1023-1059 : 1032-1037

Metaprotella solitaria sp. nov.

( Figures 5 – 7 )

Type material

Holotypeı maleı 7.55 mmı AM P.101914 ı 30 °12 ʹ 19 ʺ S 153°15 ʹ 55 ʺ Eı coral zone on rocksı South Solitary Islandı Solitary Islandsı New South Walesı brown algaeı 8 m depthı 5 February 1996 ı coll. I. Takeuchi. Paratypesı 1 maleı AM P.48618 ı 30 °12 ʹ 19 ʺ S 153°15 ʹ 55 ʺ Eı coral zone on rocksı South Solitary Islandı Solitary Islandsı New South Walesı brown algaı 12 m depthı 5 February 1996 ı coll. I. Takeuchi; 3 malesı AM P.48621 ı 30 °12 ʹ 19 ʺ S 153°15 ʹ 55 ʺ Eı coral zone on rocksı South Solitary Islandı Solitary Islandsı New South Walesı brown algaeı 8 m depthı 5 February 1996 ı coll. I. Takeuchi; 1 maleı AM P.48638 ı 29 °55 ʹ 30 ʺ S 153°23 ʹ 14 ʺ Eı ‘ The Canyons ’ ı off North Solitary Islandı Solitary Islandsı New South Walesı brown algaı Lorophora variegata on top of rocksı 7 m depthı 8 February 1996 ı coll. I. Takeuchi; 1 premature femaleı AM P.48657 ı 29 °55 ʹ 30 ʺ S 153°23 ʹ 14 ʺ Eı ‘ The Canyons ’ ı off North Solitary Islandı New South Walesı hydroids on top of rocksı 6 m depthı 8 February 1996 ı coll. I. Takeuchi; 1 mature femaleı AM P.48658 ı 29 °55 ʹ 30 ʺ S 153°23 ʹ 14 ʺ Eı ‘ The Canyons ’ ı off North Solitary Islandı Solitary Islandsı New South Walesı hydroids on top of rocksı 6 m depthı 8 February 1996 ı coll. I. Takeuchi; 1 maleı 1 mature femaleı 1 juvenileı AM P.48659 ı 29 °55 ʹ 30 ʺ S 153°23 ʹ 14 ʺ Eı ‘ The Canyons ’ ı off North Solitary Islandı Solitary Islandsı New South Walesı hydroids on top of rocksı 6 m depthı 8 February 1996 ı coll. I. Takeuchi .

Additional material examined

One maleı 2 mature and 3 immature femalesı 4 juvenilesı AM P.47829 ı 33 °49 ʹ S 151°20 ʹ Eı east of North Headı Port Jacksonı New South Walesı 21.3 m depthı Australian Museum Shelf Benthic Surveyı 20 February 1970 .

Type locality

Solitary Islandsı New South Walesı Australia.

Other locality

East of North Headı Port Jacksonı New South Walesı Australia.

Description

Holotype, male ı body length 7.55 mmı AM P. 101914. Head 0.48 mm; pereonite 1ı 0.20 mm; pereonite 2ı 1.30 mm; pereonite 3ı 1.74 mm; pereonite 4ı 1.74 mm; pereonite 5ı 1.53 mm. Pereonites 6 – 7 completely fusedı 0.57 mm.

Head/pereonite 1 fused (suture present) with paired dorsal projectionsı eyes largeı distinctive. Antenna 1 slenderı 0.65 × body length; peduncle article 2 longest; flagellum 0.6 × peduncular lengthı with 12 articlesı proximal article composed of 3 fused articles. Antenna 2 ı 0.6 × antenna 1 length; flagellum about 1/5 (0.2 ×) of peduncular length.

Upper lip notchedı forming rounded quadrilateral projections. Mandible right incisor with 5 teeth; lacinia mobilis presentı with 2 bundled setal rows; palp 3-articulateı palp article 2 with 8 lateral setae; palp article 3 setal formula 1 – 9 – 1; molar well developed with flake; left incisor with 5 teeth; lacinia mobilis with 5 teethı with 3 bundled setal rows; palp 3-articulateı palp article 2 with 10 lateral setae; palp article 3 setal formula 1 – 8 – 1. 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 seta and 5 triangular projectionsı each with a slender or robust setaı with a row of 4 slender setae. Maxilla 2 inner plate with about 8 apical robust setae; outer plate elongated with 14 apical setae. Maxilliped basal endite (inner plate) with 1 small nodular setaı with 4 setae near distal margin; ischial endite (outer plate) 2 × length of basal endite (inner plate)ı inner margin minutely serrateı with many fine setaeı with 2 setae on inner marginı with 1 seta on outer margin; palp article 2 setose on inner margin; palp article 3 with distal projectionı with moderately dense distal setae; palp article 4 (dactylus) weakly falcate.

Pereon. Pereonite 2 with anterolateral triangular projectionı with midlateral projectionı with paired anteriorly curved mid-dorsal projections. Pereonite 3 with rounded anterolateral projectionı with paired mid-dorsal projectionsı with triangular posterodorsal projection. Pereonite 4 with anterolateral projection with slight broad mid-dorsal hump. Pereonite 5 with tiny anterolateral projection.

Gnathopod 1 carpus and propodus setose; propodus subtrianguları with 3 – 4 rows of submarginal setae near anterior marginı propodus palm begins less than 0.25 along posterior margin of propodusı propodus palm minutely serrateı propodus with 1 robust seta near corner of palm; dactylus slightly curved. Gnathopod 2 begins 1/5 (0.20) along anterior margin of corresponding pereonite; coxa vestigial; basisı 0.75 × length of pereonite 2ı with anterodistal projection; ischium with distal projection; carpus 0.6 × propodus length; propodus largeı elongate (subrectangular)ı length 2 × widthı propodus anterodistal margin straightı propodus with small anterodistal rounded projection; palm proximal projection with 1 robust (grasping) setaı palm margin convexı minutely serrateı with midpalmar projectionı with deepı narrow sinusı with broadı well-developed distal shelfı shelf with two triangular projections distally.

Gill 3 ovateı 0.35 × corresponding pereoniteı straight. Pereopod 3 with 1 articleı length 5 × widthı with 8 distal setae. Gill 4 ovateı 0.3 × corresponding pereoniteı straight. Pereopod 4 with 1 articleı length 5.5 × widthı with 7 distal setae.

Pereopod 5 slender; basis shorter than propodus; carpus with ca. 10 setae on anterior to distal margin; propodus with 1 pair of robust setae from 1/3 on anterior marginı with 2 robust and 1 short setae along palm; dactylus curvedı not setose. Pereopod 6 more robust than pereopod 5; propodus more setose than pereopod 5. Pereopod 7 similar to pereopod 6; propodus more setose than pereopod 6.

Pleon. Pleopods absent. Uropod 1 probably bi-articulate (suture unclear); peduncleı length about 0.8 × widthı with 1 – 2 lateral setae; ramus length 0.5 × widthı with about 10 short distal setae. Telson present.

Paratype, mature female (sexually dimorphic characters)ı body length 4.73 mm. AM P.48658. Head 0.33 mm; pereonite 1ı 0.10 mm; pereonite 2ı 0.90 mm; pereonite 3ı 1.09 mm; pereonite 4ı 0.91 mm; pereonite 5ı 0.99 mm; pereonites 6 and 7 combined 0.41 mm. Pereonite 4 with rounded anterolateral projectionı with paired small mid-dorsal projections. Gnathopod 2 begins 0.15 along anterior margin of corresponding pereonite; propodus elongateı length 2.3 × widthı propodus palm with poorly developed triangular projectionı with poorly developed distal shelf.

Etymology

Named for the type localityı Solitary Islands.

Remarks

Metaprotella solitaria sp. nov. is close to M. guileri sp. nov. and M. haswelliana (Mayerı 1882) . Metaprotella solitaria sp. nov. differs from M. guileri sp. nov. by the following diagnostic characters: (1) M. solitaria sp. nov. possesses distinct mid-dorsal and posterodorsal projections on pereonites 2 and 3 in malesı while M. guileri sp. nov. has small projections on these pereonites; and (2) in M. solitaria sp. nov. the gills are ovateı while those in M. guileri sp. nov. are elongated.

Comparison of the observations between M. solitari a sp. nov. and the specimens of M. haswelliana from Western Australia (see Takeuchi and Lowry 2007a) confirmed the following differences of diagnostic characters: (1) in M. solitaria sp. nov. the posterodorsal projection on pereonite 2 is slightly turnedı while in M. haswelliana it is anteriorly hooked; (2) in M. solitaria sp. nov. the posterodorsal projection on pereonite 3 is smallı while in M. haswelliana it is anteriorly hooked; (3) in M. solitaria sp. nov. gnathopod 2 lacks a triangular projection near the apical end of the dorsal surfaceı while in M. haswelliana it is present; and (4) gills are oval in M. solitaria sp. nov. ı while they are twisted in M. haswelliana .

Figures

Figure 5. Metaprotella solitaria sp. nov. from South Solitary Island and off North Solitary Island, Solitary Islands, New South Wales. Holotype, male, 7.55 mm, AM P.101914; paratype, female, 4.73 mm, AM P.48658. Bar indicates 1.0 mm.

Figure 6. Metaprotella solitaria sp. nov. from South Solitary Island, Solitary Islands, New South Wales. Holotype, male, 7.55 mm, AM P.101914. Bars indicate 0.05 mm.

Figure 7. Metaprotella solitaria sp. nov. from South Solitary Island, Solitary Islands, New South Wales. Holotype, male, 7.55 mm, AM P.101914; paratype, female, 4.73 mm, AM P.48658. Bars indicate 0.2 mm.