Agononida africerta Poore & Andreakis 2012
Creators: name: Poore, Gary C. B.
name: Andreakis, Nikos
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Galatheidae
Agononida
Agononida africerta

description: Agononida africerta Poore & Andreakis, 2012
(Figs 2 a, 3)
Agononida africerta Poore & Andreakis, 2012: 10 –16, figs 2D, E, 3C, 8.
Material examined. Holotype and paratypes from off Mozambique as listed by Poore & Andreakis (2012): MNHN IU- 2008-10192*, IU- 2008-10435*, IU- 2008-10436*, IU- 2008-10438*, IU- 2008-10440, IU- 2008-10441*, IU- 2008-10442.
Other material. MADAGASCAR. Between Nosy-bé and Banc du Leven: 12°26'S, 48°13'E, 578–580 m (MIRIKY stn CP3192), MNHN IU- 2010-1158* (male, 21 mm; 5 females, 10–17 mm); 12°30'S, 48°08'E, 691–695 m (MIRIKY stn CP3187), MNHN IU- 2010-1154 (15 individuals); 12°40'S, 48°12'E, 492–524 m (MIRIKY stn CP3184), MNHN IU- 2009-1892* (male, 14 mm), MNHN IU- 2010-1155* (male, 16 mm; female, 16 mm); 12°31'S, 48°15'E, 415–416 m (MIRIKY stn CP3190), MNHN IU- 2010-1150* (ovigerous female, 16 mm); 12°34'S, 48°09'E, 613–625 m (MIRIKY stn CP3186), MNHN IU- 2010-1152* (female, 19 mm); 12°42'S, 48°11'E, 584–624 m (MIRIKY stn CP3222), MNHN IU- 2010-1156* (7 individuals), MNHN IU- 2010-1157* (2 females, 9 mm); 12°51'S, 48°08'E, 558–592 m (MIRIKY stn CP3180), MNHN IU- 2010-1153* (male, 16 mm; juvenile).
Diagnosis. Telson anterolateral margin sinusoidal, concave and smooth over anterior 60%, remainder sometimes separated by notch, strongly convex, margin almost longitudinal anterior to transverse suture, with crenellate margin. Pereopods 2–4 dactyli about 6 times as long as greatest basal width; robust setae on flexor margin of dactylus of pereopod 2 number 12–25 (median about 16, 8 exceptional); of pereopod 3, 2–9 (median 4); and of pereopod 4, 1–3. Pereopod 3 merus sometimes with 1 spine and pereopod 4 merus with 1–4 spines proximally on upper face. (revised from Poore & Andreakis 2012)
Supplementary description of male. Based on MNNH IU-2008-10192, supermale, cl. 31 mm, and male, cl. 21 mm, MNHN IU-2010-1158. Telson anterolateral margin concave over anterior three-quarters, distally this section with a denticulate upper ridge, posterior quarter separated by triangular notch, laterally irregularly denticulate.
c f Pereopod 1 of supermale 3.8 times as long as carapace, merus as long as carapace, carpus 0.7 times as long as merus, propodus 1.9 times as long as merus, fingers 0.5 times as long as total propodus length. Merus with 1+7 spines along upper margin, 1+4 spines along mesial face, 1+18 spines along lateral face, with 3 elevated scales on lower margin; carpus with 1+2 spines on upper margin, 1+2 spines on mesial face, 1+2 spines on lateral face; propodus square in cross-section, with 0+5 spines on upper margin, with 1+2 spines along mesial face, with 1 spine on lateral face near base of dactylus, with 1 spine on lower margin; fixed finger with 1 smooth proximal tooth, a wide concave hiatus and second complex tooth; dactylus cutting edge with 2 closely placed proximal teeth. Pereopods 2–4 meri each with 15–18 spines along extensor margin, 8–11 on flexor margin.
Colour. From 3 photos of paratypes (MNHN IU-2008-10190, IU-2008-10191, IU-2009-1892) but see remark below. Carapace and abdominal somites 1–3 generally orange, stronger around bases of spines and rostrum. Pereopods 1–4 meri orange-red, spines and squamae of pereopods more strongly coloured than elsewhere. Pereopod 1 with diffuse orange patches at carpus-propodus joint and bases of fingers. Pereopods 2–4 with orange spot at base of carpus and propodus, distal two-thirds of dactyli, especially of pereopods 3 and 4 bright red. Antennal flagellum red except distally.
Distribution. Between Madagascar and Mozambique, 12°S–25°S; 446–695 m (median 508 m) depth.
Remarks. The new material confirms the presence of A. africerta along the full length of the channel between Mozambique and Madagascar to almost 700 m depth. Agononida africerta overlaps with A. madagascerta at the northern limit of its range. However, despite the overlapping distribution, a high genetic differentiation was recovered between these two species, with A. africerta genealogically closely related to A. vanuacerta and A. indocerta in clade A, while A. madagascerta was found basal in clade B.
Our earlier description of the colour pattern of this species and colour-photo of a supermale seem now not to be typical (Poore and Andreakis 2012: Fig. 3 C). The distinctive colour pattern based on three photos shows the species to have distinctive red-tipped pereopodal dactyli not seen on the stronger dactyli of the supermale. The males illustrated here (Figs 3 a, b, d) are larger than that figured by us earlier (2012: Fig. 8 D), vary considerably and may have a more obvious notch separating the anterior from lateral regions of the anterolateral margin of the telson. The cheliped of the supermale has prominent teeth and dense mats of long setae in the gape (Fig. 3 f). That of the female is moderately squamose (Fig. 3 e).
The median numbers of robust setae on pereopods 2 and 3 are slightly lower than the figures given in the original description. The number on pereopod 2 (median 16) is greater than those on the sympatric species, A. madagascerta (median 6). The two species can also be distinguished on the basis of colour. Agononida africerta has one or more spines on the upper face of the merus of pereopod 4, a condition seen elsewhere only in A. indocerta, A. polycerta and A. vanuacerta n. sp.. Some specimens of A. africerta have a spine in a similar position on pereopod 3. The anterolateral margin of the telson also differs between the two species. A notch separates the anterior two-thirds from the posterior lobe in all A. madagascerta but is absent in A. africerta, except in larger males (see Figs 3 a, d).
Agononida africerta and A. vanuacerta are almost indistinguishable morphologically (see discussion under latter).
description: Published as part of Poore, Gary C. B. & Andreakis, Nikos, 2014, More species of the Agononida incerta complex revealed by molecules and morphology (Crustacea: Decapoda: Anomura: Munididae), pp. 201-225 in Zootaxa 3860 (3) on pages 205-207, DOI: 10.11646/zootaxa.3860.3.1, http://zenodo.org/record/228955