Agononida incerta ( Henderson, 1888 )

Poore, Gary C. B. & Andreakis, Nikos, 2014, More species of the Agononida incerta complex revealed by molecules and morphology (Crustacea: Decapoda: Anomura: Munididae), Zootaxa 3860 (3), pp. 201-225 : 209-210

Agononida incerta ( Henderson, 1888)

( Fig. 4 b)

Munida incerta Henderson, 1888: 130 , pl. 13, figs 4, 4a.

Agononida incerta .— Poore et al. 2008: 18 (part). – Baba et al. 2009: 76–78, fig. 63.— Poore & Andreakis 2012: 7–10, figs 2A–C, 3A, 3B, 4–7.

Material examined. INDONESIA. Kepulauan Kei: 5.35°S, 132.5° E, 329–389 m (KARUBAR stn CC10), MNHN IU- 2010-6100* (supermale), MNHN IU- 2010-6101* (ovigerous female); 5.817°S, 132.3°E, 296–299 m (KARUBAR stn CP05), MNHN IU- 2010-6102* (female), MNHN IU- 2010-6103* (male); 6.133°S, 132.75°E, 390–502 m (KARUBAR stn CP35), MNHN IU- 2010-6104* (male), MNHN IU- 2010-6105* (female).

PHILIPPINES. E of Mindoro I.: 13°08'N, 122°39'E, 280–340 m (Coriolis stn CP40), MNHN IU- 2010-6111* (ovigerous female), MNHN IU- 2010-6112* (male).

TONGA. N of Eua: 21°16'S, 174°59'W, 483–509 m (BORDAU 2 stn CP1527), MNHN IU- 2010-6122* (male), MNHN IU- 2010-6123* (female), MNHN IU- 2010-6124* (ovigerous female), MNHN IU- 2010-6125* (female).

Diagnosis. Telson anterolateral margin quasi-3-lobed, middle lobe largest, with sharp edge, deflected dorsally, separated from weak anterior lobe by shallow concavity and from more rounded thicker posterior lobe by deep notch, exaggerated in males, finely crenellate over posterior two-thirds in larger individuals. Pereopods 2–4 with dactyli 5.1–6.6 times as long as greatest basal width; robust setae on dactylus of pereopod 2 number 12–30 (median 17, rarely 4), of pereopod 3, 2–10 (median 6, rarely 1–17), and of pereopod 4, 1–3 (rarely 6). Pereopod 4 merus without spines proximally on upper face. (Revised from Poore & Andreakis 2012)

Distribution. Taiwan, Philippines, eastern Indonesia, to southern Western Australia, Tonga; 22°N–24°S; 280–509 m (median 403 m) depth. Possibly as far north as central Japan (c. 35°N) if published records are corroborated ( Poore & Andreakis 2012)

Remarks. Agononida incerta is distinguished from other species in the genus by the number of robust setae on pereopodal dactyli 2 and 3, up to 30 and 17 respectively (usually around 17 and 6). These numbers are similar to those on A. indocerta and A. africerta , species that differ in usually having facial spines on the merus of pereopod 4. The number of robust setae on pereopod 3 in the sympatric species A. indocerta is usually higher, with a median number of about 17. The anterolateral margin of the telson of A. incerta , notably in adult males ( Fig. 4 b) but also in large females ( Fig. 4 c) the large middle lobe has a sharp edge deflected dorsally, separated from weak anterior lobe by shallow concavity and from more rounded thicker posterior lobe by a deep notch.

The new material expands the distribution of this species eastwards to Tonga but no other records exist between Tonga and the eastern islands of Indonesia ( Fig. 1 ). Agononida incerta showed the widest geographical distribution range of all in this complex. The species was recovered basal to sister species A. auscerta and A. rubrizonata of clade B in all molecular analyses.

Figures

FIGURE 1. Distribution (based on 189 museum records) of ten species of the Agononida incerta complex in the Indo-West Pacific, largely in the Southern Hemisphere, separated into two clades, A and B; overlaid by a model-constrained maximumlikelihood phylogeny inferred from 6 COI and 5 16 S new sequences merged with previously produced molecular data. Bootstrap support values for species are given. Species of clade A – A. africerta, yellow circle (12); A. indocerta, red triangle (18); A. polycerta, blue square (4); A. vanuacerta, white triangle (2). Species of clade B – A. auscerta, black asterisk (11); A. incerta, blue square (20); A. madagascerta, black triangle (3); A. rubrizonata, red triangle (34); A. tasmancerta, white square (8). Numbers of records are in parentheses. A. tasmancerta does not appear in the phylogeny. Agononida incerta is likely to occur further north than these records indicate, as far as central Japan.

FIGURE 4. Agononida auscerta. Pereopods 1, upper and lateral views: a, ovigerous female, 24 mm, NMV J 55995. Agononida incerta. Anterolateral margin of telson: b, ovigerous female, 24 mm, NMV J 5521; c, male, 28 mm, NMV J 55025.