Melita lowryi, Springthorpe, 2023

Springthorpe, Roger T., 2023, Melita lowryi, a New Species of Melitidae (Crustacea: Amphipoda: Senticaudata) from New Zealand, and the Redescription of Melita festiva (Chilton, 1885) from Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 547-558 : 553-556

Melita lowryi sp. nov.

urn:lsid:zoobank.org:act:A2E7E665-E8E8-4442-93E3-71CE20A9879F

Figs 5–7

Melita festiva Chilton, 1916: 359 , figs 1, 2.—J. L. Barnard, 1972: 117.

? Melita festiva .— Hurley, 1957: 6.— Fenwick, 1976: 2.

Not Ledoyeromelita festiva . — Labay, 2016: 65.

Holotype: Male (ca. 12.5 mm; 5 micro slides A1–5), CMNZ 2015.149 .4190, Rangitoto Reef, Auckland Harbour, New Zealand, 36°47'S 174°49.5'E, under stones, coll. W. R. B. Oliver . Paratype: Ovigerous female (12.5 mm; 2 micro slides B1–2), CMNZ 2015.149 .4191, same data as holotype .

Type locality. Rangitoto Reef , Auckland Harbour, New Zealand, 36°47'S 174°49.5'E.

Description. Based on holotype male, ca. 12.5 mm, CMNZ 2015.149.4190.

Head. Anteroventral margin with large notch on anteroventral corner, anteroventral corner rounded; eyes present, well developed. Antenna 1 longer than antenna 2, peduncular article 1 shorter than 2 with 4 robust setae along posterior margin, article 2 longer than article 3; accessory flagellum 5-articulate; flagellum 20-articulate. Antenna 2 peduncular article 4 subequal to article 5; flagellum strongly setose, 13-articulate. Mandible molar unknown (not present on slides), setal row well developed; palp well-developed, 3-articulate; article 1 not produced distally, length 0.5 times article 2, article 2 length 0.8 times article 3 with several marginal setae, article 3 rectilinear with a bunch of apical setae and several marginal setae. Maxilla 1 inner plate long, subrectangular, with 8 apical plumose setae, outer plate with 9 apical setal teeth, palp 2-articulate, slightly curved with numerous apical and subapical setae. Maxilla 2 inner plate without oblique setal row on inner face, with marginal setal row. Maxilliped plates strong, palp article 2 rectilinear, dactyl curved.

Pereon. Coxae 1–3 without posteroventral cusp. Gnathopod 1 not sexually dimorphic, subchelate; coxa anteroventral corner produced, rounded, anterior margin slightly concave; carpus about 2 times longer than broad, length 1.2 times propodus; propodus small, linear, without hump along anterior margin, without anterodistal projection or hood, posterodistal margin not swollen; palm convex, entire, without anterodistal projection near base of dactylus; dactylus articulating distinctly with propodus, well developed, fitting palm, posterior margin not swollen at base. Gnathopod 2 significantly enlarged in male, sexually dimorphic; left and right gnathopods subequal in size, subchelate; merus with sharply produced posterodistal process; carpus compressed, length about 0.5 times breadth, posterior margin lobate; propodus expanded, with a few rows of setae along anterior and posterior margins, palm slightly acute, with a row of simple setae along lateral margin, with large truncate mid palmar tooth, and one large rounded proximal tooth, posterodistal corner subquadrate with 2 robust setae medially; dactylus apically truncate, hammer-like, closing along palm. Pereopod 4 smaller than pereopod 3, coxa with posteroventral lobe. Pereopods 5–7 similar in shape; merus, carpus, and propodus not densely setose, with bunches of slender setae along anterior margin, posterior margin sparsely setose. Pereopod 5 smaller than pereopods 6–7; basis expanded, posterior margin almost straight, minutely serrate, posteroventral corner broadly rounded; dactylar unguis bifid. Pereopod 6 coxa sexually dimorphic, anterior lobe slightly produced, rounded. Pereopod 7 subequal in size to pereopod 6.

Pleon. Pleonites 1–3 without dorsal teeth, spines or setae. Epimeron 1 posteroventral corner subquadrate. Epimeron 2 posteroventral corner subquadrate. Epimeron 3 posterior margin smooth with several minute setae, ventral margin serrate along posterior half, with several small robust setae along anterior half, posteroventral corner with strongly produced acute tooth. Urosomite 1 with one dorsal mid-line spine. Urosomite 2 with 4 dorsal spines, with 2 dorsal robust setae in 2 groups. Uropod 1 peduncle with basofacial robust seta. Uropod 3 inner ramus scale-like, much shorter than outer ramus, outer ramus long, length 8.5 times breadth, 2-articulate, article 2 short. Telson deeply cleft, longer than broad, lobes apically acute, with 2 subapical robust setae on each lobe, robust setae along outer margins absent, one minute seta on inner margin of each lobe.

Female (Sexually dimorphic characters). Based on paratype female, 12.5 mm, CMNZ 2015.149.4191. Oostegites linear, sparsely setose, present on gnathopod 2 and pereopods 3–5. Gnathopod 2 carpus short, length 1.4 times breadth, posterior margin not lobate; propodus subovate, length 1.7 times carpus, palm acute, cuspidate, corner defined by acute tooth and 2 robust setae; dactylus apically acute, closing along palm. Pereopod 6 coxa anterior lobe slightly produced, bilobate.

Habitat. Marine, rocky intertidal algae to 11 m depth.

Etymology. Named for Jim Lowry, friend and colleague, for his vast contribution to the taxonomy and natural history of the Amphipoda .

Remarks. The differences between Melita lowryi sp. nov. and Melita festiva ( Chilton, 1885) are discussed under Melita festiva above. Both species can be distinguished from other Melita by the shape of gnathopod 2 propodus and dactylus, and the bifid anterior lobe of female coxa 6.

Distribution. New Zealand. Rangitoto Reef, Auckland Harbour, North Island ( Chilton, 1916);?Cook Strait ( Hurley, 1957); Kaikoura, South Island ( Fenwick, 1976).

Figures

Figure 5. Melita lowryi sp. nov., holotype male, ca. 12 mm, CMNZ 2015.149.4190, Rangitoto Reef, Auckland Harbour, New Zealand; paratype female, 12.5 mm, CMNZ 2015.149.4191, same data. Scale lines represent 0.2 mm.

Figure 6. Melita lowryi sp. nov., holotype male, ca. 12 mm, CMNZ 2015.149.4190, Rangitoto Reef, Auckland Harbour, New Zealand; paratype female, 12.5 mm, CMNZ 2015.149.4191, same data. Scale lines represent 0.5 mm.

Figure 7. Melita lowryi sp. nov., holotype male, ca. 12 mm, CMNZ 2015.149.4190, Rangitoto Reef, Auckland Harbour, New Zealand; paratype female, 12.5 mm, CMNZ 2015.149.4191, same data. Scale lines for P5–7 represent 0.5 mm; remainder represent 0.2 mm.