Maeraceterus taaroa, Hughes, Lauren E., 2016

Hughes, Lauren E., 2016, New genera, species and records of Maeridae from Australian Waters: Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov., Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda), Zootaxa 4115 (1), pp. 1-81 : 76-79

Maeraceterus taaroa sp. nov.

( Figs 63–64 )

Type material. Holotype male, 8.2 mm, dissected, 4 slides, AM P.81539, Cathedral Rock , Norfolk Island, South Pacific (29°00′13″S 167°56′57″E), 10.9 m, under stones, 13 May 2008, coll. R.T. Springthorpe (MI NFK 7).

Type locality. Cathedral Rock , Norfolk Island, South Pacific (29°00′13″S 167°56′57″E).

Etymology. Name from the Polynesian sea god, Taaroa ; used as a noun in apposition.

Description. Based on holotype male, 8.2 mm, AM P.81539.

Head. Eyes subovate; lateral cephalic lobe broad, apically rounded, anteroventral margin with notch/slit, anteroventral corner truncate. Antenna 1 unknown. Antenna 2 peduncular article 4 longer in length than article 5; flagellum with 10 articles. Mandible accessory setal row, well developed with 5 setae; palp well developed, article 1 length 1.1 × width, shorter than article 2; article 2 longer than article 3, with a few slender setae; article 3 rectilinear, long, 3.1 × as long as broad, longer than article 1, with 4 apical slender setae. Lower lip lobes without apical ducts; mandibular lobes apically rounded. Maxilla 1 inner plate with 3 apical setae; outer plate palp with apical slender setae.

Pereon. Gnathopod 1 coxa anterior margin concave, anteroventral corner produced, subacute to narrowly rounded, posteroventral corner without notch; merus with posteroventral corner subquadrate; carpus length 2.1 × width, 1.3 × propodus length, medial surface with rows of short setae; propodus rectilinear, medial surface setal comb absent, palm subacute, straight, entire, defined posterodistal corner with 2 robust setae; dactylus closing along palm.palm subacute, straight, entire, defined posterodistal corner with 2 robust setae; dactylus closing along palm.

Gnathopod 2 symmetrical, subchelate; coxa posteroventral corner without notch; basis broad, anterodistal corner with pair of well-developed rounded lobes, posterodistal corner with row of long robust setae; ischium anterior margin with pair of well-developed lobes; merus with subacute posteroventral corner; carpus compressed, length subequal to width, posterior margin with long slender setae; propodus subovate, length twice width, posterior margin with clusters of long slender setae, palm angle subacute, posterodistal shelf subrectangular, margin sculpted, with 2 rounded teeth, palm weakly defined by 1 robust seta; dactylus closing along and reaching end of palm.

Pereopod 4 coxa without posterodistal lobe. Pereopods 5–7 slender distally; basis posteriorly expanded, margin weakly convex, without long slender setae; merus and carpus slightly broadened; dactylus unguis simple.

Pleon. Pleonites 1–3 dorsally smooth. Epimeron 1 posterior margin smooth, corner subquadrate. Epimeron 2 posterior margin smooth, corner with notch and small tooth. Epimeron 3 posterior margin smooth, corner subquadrate. Urosomites 1–3 without carina. Uropod 1 peduncle with 1 basofacial seta; rami inner ramus longer than outer ramus; outer ramus 0.9 × peduncle length. Uropod 2 peduncle with 1 basofacial seta; rami inner ramus longer than outer ramus; outer ramus 0.9 × peduncle length. Uropod 3 unknown. Telson deeply cleft, length subequal to width, lobes divergent, tapering distally, lobes apical margins concave, inner cusps shorter than outer cusps, each lobe with 4–6 apical robust setae and 1 pair of lateral robust setae.

Remarks. See remarks for Maeraceterus bramblensis gen. et sp. nov.

Distribution. South Pacific. Norfolk Island (current study).

Figures

FIGURE 63. Maeraceterus taaroa gen. et sp. nov., holotype male, 8.2 mm, AM P. 81539, Cathedral Rock, Norfolk Island, scales 0.1 mm.

FIGURE 64.. Maeraceterus taaroa gen. et sp. nov., holotype male, 8.2 mm, AM P. 81539, Cathedral Rock, Norfolk Island, scales 0.1 mm.