Manawataawhiorchestia uruone, Myers & J.-P & Shepherd, 2025

MYERS, ALAN A., BALL, OLIVIER J. - P. & SHEPHERD, LARA D., 2025, A new landhopper, Manawataawhiorchestia uruone gen. nov., sp. nov. (Amphipoda: Talitroidea: Talitridae) from Manawatāwhi / Three Kings Islands, New Zealand, Zootaxa 5637 (2), pp. 363-373 : 365-369

Manawataawhiorchestia uruone sp. nov.

( Figs 2–5 )

Material examined. Type material. Holotype: male ( MNZ CR.027895 ), dissected, body length 8.0 mm, North East Island, Three Kings Islands , New Zealand ( Fig. 1 ), Meryta -Metrosideros forest at north end of island, coll. Brook F., 6 November 2008. Allotype: female ( MNZ CR.027896 ), body length 9.0 mm, same data as holotype . Paratypes: 1 female, 1 semi-juvenile male ( MNZ CR.027897 ), same data as holotype .

Etymology. Assigned by local Māori, the name signifies the migration from sand to land enlivening the pulsating heartbeat of Manawatāwhi. Uruone showcases the delicate balance between ecosystems and the need to amplify the status of all species for their protection and the survival of humanity. Ora Taiao, oranga tangata (when the environment is pristine, human potential is endless).

Description. Adult male (approximately 8 mm long).

Head. Eye medium, 1/4 head length. Antenna 1 reaching to at least midpoint of peduncular article 5 of antenna 2; flagellum shorter than peduncle with 4–5 articles, the terminal article rudimentary. Antenna 2 peduncular article 4 broad, article 5 slender; flagellum with 8 articles. Mandible left lacinia mobilis 4-cuspidate. Maxilliped palp broad, article 2 with distomedial lobe, article 3 broad, fourth article absent (perhaps fused with article 3).

Pereon. Gnathopod 1 sexually dimorphic, subchelate; merus without palmate lobe; carpus longer than propodus and lacking palmate lobe; propodus anterior margin with 3 groups of robust setae, propodus subrectangular with well-developed posterodistal palmate lobe, palm transverse. Gnathopod 2 sexually dimorphic, semi-mascupod; carpus slender, elongate; propodus enlarged with posterodistal lobe covered in palmate setae. Pereopod 3 dactylus basidactylate. Pereopod 4 dactylus amplidactylate. Pereopods 5–7 weakly bicuspidactylate. Pereopod 5 short, about 2/3 length of pereopod 6, merus broad, 1.5 times longer than broad at widest point, expanded distally; dactylus long, slender, not inflated. Pereopod 6 not sexually dimorphic; basis expanded, subovate to elliptical. Pereopod 7 not sexually dimorphic; basis expanded, suborbicular, slightly broader than long.

Pleon. Pleopods 1–3 all well-developed, peduncle lateral margins with long robust setae, rami non-segmented. Pleopod 1 peduncle stout basally; exopodite with long robust setae, endopodite shorter and narrower than exopodite and without marginal setae. Pleopod 2 shorter than pleopod 1 (0.6 times length), rami subequal, short, weakly setiferous. Pleopod 3 shortest (0.5 times length of pleopod1), rami subequal, short, without marginal setae. Epimera 1–3 rounded ventrally. Epimeron 3 posterior margin weakly scalloped. Uropod 1 peduncle longer than rami, lacking distolateral robust seta; exopodite with 2 marginal robust setae in one row, endopodite with 2 rows of marginal robust setae, 2 marginal robust setae on the mesial margin, and 1–2 smaller marginal robust setae on lateral margin (when viewed dorsally). Uropod 2 peduncle subequal with rami; exopodite with 2 marginal robust setae, endopodite with 2 rows of 1–2 marginal robust setae on the mesial and lateral margins (those on the lateral margin slightly smaller). Uropod 3 peduncle slightly longer than ramus, with 2–3 robust setae distally; ramus with many apical and marginal robust setae. Telson as broad as long, rounded distally, with complete dorsal ridge and ringed with 5–6 marginal robust setae per lobe.

Female (sexually dimorphic characters only). Adult females approximately 7–9 mm long. Gnathopod 1 similar to that of male, but propodus, simple and lacking palmate lobe. Gnathopod 2 mitten-shaped; carpus slender, longer than propodus; propodus slender, subovoid. Oostegites broad.

Remarks. Evidence suggests Manawataawhiorchestia uruone sp. nov. is a semi-mascupod exhibiting weak to moderate sexual dimorphism. Further modification of the male gnathopod 2 in larger males cannot be discounted although it is doubtful if it would then resemble the mascupod form represented by other New Zealand or world Talitridae (see rationale for this in the discussion). Neoteny is well known in many talitroids in the families Arcitalitridae , Brevitalitridae and Makawidae where they are known as femipods ( Myers & Lowry 2020) but neoteny is very rare in the Talitridae , being found to date in one sandhopper genus only ( Talitrus ).

The existence of Manawataawhiorchestia uruone sp. nov. was previously noted as Genus N in Ball et al. (2024).

Distribution. Three Kings Islands (North East Island and Great Island).

Habitat. Known from leaf litter and decaying wood from coastal forest, including Meryta sinclairii -Metrosideros excelsa forest.

Figures

FIGURE 1. Map showing location of the Three Kings Islands, including North East Island and Great Island where Manawataawhiorchestia uruone sp. nov. was collected, relative to the New Zealand mainland.

FIGURE 2. Manawataawhiorchestia uruone sp. nov. male holotype, North East Island, Three Kings, from 70% ethanol. Inset: colouration after more recent preservation.

FIGURE 3. Manawataawhiorchestia uruone sp. nov. male holotype (head, antennae, maxilliped, pleopods 1–3, epimera 1– 3, uropods 1–3, telson), North East Island, Three Kings. Manawataawhiorchestia uruone sp. nov. female (oostegite), North East Island, Three Kings. Scale bars: A = maxilliped, uropod 3, telson; B = uropods 1–2, pleopods 1–3, oostegite; C = head, epimera.

FIGURE 4. Manawataawhiorchestia uruone sp. nov. male holotype (gnathopod 1 and 2), North East Island, Three Kings. Manawataawhiorchestia uruone sp. nov. female (gnathopod 1 and 2), North East Island, Three Kings.

FIGURE 5. Manawataawhiorchestia uruone sp. nov. male holotype (pereopod 4 dactyl, pereopods 5–7), North East Island, Three Kings.