Tegano atkinsae, Lowry & Springthorpe, 2009

Lowry, J. K. & Springthorpe, R. T., 2009, Melitidae, the Melita group *, Zootaxa 2260 (1), pp. 718-735 : 730-734

Tegano atkinsae sp. nov.

( Figs 8 , 9 )

Type material. Holotype, male, 5.0 mm, AM P77777, Ferriers Creek , Lizard Island, Queensland, Australia (14°39.95’S 145°27.05’E), algae from among roots at edge of mangroves ( Rhizophora stylosa ), surface, A. Myers, 25 February 2005 ( QLD 1680 ) . Paratypes: 1 male, 5.2 mm, AM P77961 ( JDT / LIZ 4 ) ; 1 female, 4.3 mm, AM P77778 ; 10 males, 3 females, AM P70900 ( QLD 1680 ) ; 8 males, 4 females, AM P77960 ( JDT / LIZ 4 ) ; 2 specimens AM P70803 ( QLD 1655 ) ; 1 female, AM P70925 ( QLD 1677 ) .

Type locality. Ferriers Creek , Lizard Island, Queensland, Australia (14°39'56"S 145°27'3"E) .

Etymology. Named for Lisa Atkins, one of the great cooks of Pittwater, and provider of nourishing sustenance for the participants of the Lizard Island Amphipod Workshop.

Description. Based on holotype, male, AM P77777 and paratype female, AM P77778.

Head. Head lateral cephalic lobe broadly rounded; eyes ovate; anteroventral margin without notch-slit, excavate, anteroventral corner rounded. Antenna 1 slightly longer than antenna 2; peduncular article 1 shorter than article 2, with 2 robust setae along posterior margin; peduncular article 2 longer than article 3; accessory flagellum minute, with 3 articles (third tiny); flagellum with 11+ articles. Antenna 2 strongly setose; peduncular article 4 subequal to article 5; flagellum with 9 articles. Mandible molar medium size; accessory setal row well developed; palp reduced in size, 3-articulate; article 1 about twice as long as broad, shorter than article 2, inner margin article 1 not produced distally; article 2 longer than article 3; article 3 shorter than article 1, cone-like, with a terminal long whip-like seta. Maxilla 1 inner plate long, subrectangular, with 8 mainly apical setae. Maxilla 2 inner plate without oblique setal row, with marginal setal row. Lower lip inner lobes present. Maxilliped palp article 3, about as long as broad.

Pereon. Gnathopod 1 coxa anteroventral corner not produced, anterior margin straight, not produced, posteroventral corner notch absent; merus without posterodistal tooth; carpus about 2 x as long as broad, palm without produced lobe, carpus subequal in length to propodus, length 1.2 x propodus, without anterodistal swelling; propodus small, linear, with slight hump along anterior margin, without anterodistal projection, palm nearly transverse, sinusoidal, partially excavate, without anterodistal projection near base of dactylus, posterodistal margin slightly swollen, defined by posterodistal corner, without posterodistal robust setae; dactylus articulating distinctly with propodus, well developed, fitting palm, posterior margin swollen at base. Gnathopod 2 significantly enlarged in male and female; sexually dimorphic; subchelate; coxa posteroventral corner notch absent; carpus short, length 1.2 x breadth, not lobate, not enclosed by merus and propodus; merus acutely produced distoventrally; propodus expanded, without strong concentration of setae, propodus with medial depression, forming distomedial hollow, palm acute in male and female, palm acute with well defined corner, sinusoidal, smooth, with group of anterodistal robust setae, without teeth along margin, defined by posteroventral corner, without posterodistal robust setae, with well defined corner in male and female, male both propodi with well defined corner (greater than 90º); dactylus closing across medial surface of propodus, reaching end of palm, with 1 or 2 setae on anterior margin, inner margin smooth, apically acute/ subacute. Pereopod 4 coxa posteroventral lobe absent, posterior margin straight. Pereopod 5 basis slightly expanded; posterior margin slightly convex, posteroventral corner narrowly rounded or subquadrate. Pereopod 6 coxa not sexually dimorphic, slightly produced, rounded; basis posterior margin straight, posteroventral corner subquadrate. Pereopod 7 basis posterior margin expanded posteroproximally, tapering distally, posterodistal corner narrowly subquadrate.

Pleon. Pleonites 1–3 dorsally smooth. Urosomite 1 without a small dorsal hump; smooth; with 1 dorsodistal spine. Urosomite 2 with 2 small dorsal robust setae. Urosomite 3 without dorsal setae. Uropod 1 peduncle without distoventral spur; with basofacial robust seta; inner ramus not modified. Uropod 2 rami slender, apically acute. Uropod 3 rami distally truncated, apical robust setae short; inner ramus scale-like, much shorter than outer ramus; outer ramus very long, length 6.5 x breadth, much longer (about 3 x) than peduncle, 2-articulate, article 2 long. Telson cleft, slightly broader than long, tapering distally, lobes apically acute or subacute, without dorsal robust setae, each lobe with 3 or more apical/subapical robust setae, with robust setae on outer margins, absent on inner margins, apical conical extension absent.

Habitat. Living in algae from among roots at edge of mangroves ( Rhizophora stylosa ).

Remarks. Tegano atkinsae sp. nov. is very similar to T. levis ( Stock & Iliffe, 1995) from New Caledonia. They differ as follows: T. atkinsae has 1 robust seta along posterior margin of antenna 1 peduncular article 1 (2 in T. levis ); T. atkinsae has a better developed antenna 2 flagellum with about 11 articles (about 5 articles in T. levis ); male gnathopod 2 palm with a group of anterodistal robust setae in T. atkinsae (with group of slender setae with 1 large, mid-palmar robust seta in T. levis ); epimera 1–3 with sparse slender setae along posterior margin in T. levis (epimera 1–2 without setae along posterior margin, epimeron 3 with 1 tiny posterodistal seta); uropod 3 outer ramus with 9 setae in 3 clumps along inner margin in T. atkinsae (about 10 setae in 5 clumps along inner margin in T. levis ).

Tegano atkinsae is also similar to T. shiodamari ( Yamato, 1995) from southern Japan. They differ as follows: T. atkinsae has 1 robust seta along posterior margin of antenna 1 peduncular article 1 (2 in T. shiodamari ); epimeron 1 with a subquadrate posterodistal corner (broadly rounded in T. shiodamari ); epimeron 2 with an acute posteroventral corner plus small spine on posterodistal ventral margin (subacute with smooth ventral margin); uropod 3 outer ramus with 9 setae in 3 clumps along inner margin (5 setae in continuous row along inner margin in T. shiodamari ).

Distribution. Australia. Queensland: Lizard Island (current study).

Figures

FIGURE 8. Tegano atkinsae sp. nov., holotype, male, 5.0 mm, AM P77777, habitus, paratype, male, 5.2 mm, AM P77961, Ferriers Creek, Lizard Island, Great Barrier Reef.

FIGURE 9. Tegano atkinsae sp. nov., holotype, male, 5.0 mm, AM P77777, paratype, female, 4.3 mm, AM P77778, Ferriers Creek, Lizard Island, Great Barrier Reef.