Agononida tasmancerta, Poore, Gary C. B. & Andreakis, Nikos, 2014

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 : 218-221

Agononida tasmancerta n. sp.

( Figs 2 i, 10)

Material examined. Holotype. AUSTRALIA. QUEENSLAND. NE of Coolangatta: 27°55'S, 154°03'E, 549 m ( Kapala stn K 78-23-09), AM P.90862 (supermale, 25 mm).

Paratypes. QUEENSLAND. Collected with holotype: AM P.90863 (female, 28 mm; ovigerous female, 21 mm), AM P.42262 (7 males, 10–25 mm; 6 females, 16–25 mm). E of Cape York: 10°29.8'S, 144°01.4'E, 596 m (Franklin stn FR 06-88-08), AM P.89034 (male, 24 mm, with Sacculina ). E of Tully: 17°52.5'S, 147°08'E, 740– 680 m (Cidaris I stn 48-3), QM W13947 (3 females, 12–15 mm; 2 males, 15, 17 mm).

NSW. NE of Tweed Heads: 28°02'S, 153°59'E, 549 m, AM P.88983 (2 males, 2 females). Off Tweed Heads: 28°10'S, 153°33'E, 600 m, AM P.46658 (male), AM P.96519 (male, 16 mm). SE of Cape Byron: 28°41'S, 153°51'E, 156 m ( Kapala stn K78-17-21), AM P.31429 (2 males, 2 females). NE of North Solitary I.: 29°48'S, 153°43.5'E, 439 m ( Kapala stn K 78-16-07), AM P.42282 (ovigerous female). E of Terrigal: 33°25'S, 152°7'E, 640 m ( Kapala stn K 75-05-04), AM P.21012 (female).

Diagnosis. Telson anterolateral margin sinusoidal, concave over anterior two-thirds; in supermale smooth except for denticles laterally, with a dorsal sharp secondary ridge, remainder prominently semicircular, coarsely denticulate and appearing as a series of blunt, squarish molar-like teeth; in female with short dorsal sharp secondary ridge, anterior section ending at obtuse angle, remainder convex, obscurely crenellate. Pereopods 2–4 with dactyli about 5–6 times as long as basal width; robust setae on flexor margin of pereopod 2 number 14–31 (median 22); of pereopod 3, 2–12 (median 8); and of pereopod 4, 1–8 (median 2). Pereopod 4 merus without spines on upper face (rarely present).

Description. Holotype, supermale, cl. 32 mm. Carapace 0.95 times as long as greatest width. Gastric region with pair of small epigastric spines. Frontal margin inclined posteriorly at 20° from midline. Rostrum spiniform, 0.41 length of carapace (both measured from base of supraocular spines); supraocular spine 0.65 length of rostrum (both measured from base of rostrum). Thoracic sternite 3 0.55 width of sternite 4; midlength of sternal plastron (sternites 4–7) 0.63 width of sternite 7.

Telson 2.0 times as wide as long; Telson anterolateral margin sinusoidal, concave over anterior two-thirds, smooth except for denticles laterally, with a dorsal sharp secondary ridge, remainder prominently semicircular, coarsely denticulate and appearing as a series of blunt, squarish molar-like teeth.

Eye with maximum corneal diameter 1.2 times basal width of supraocular spines. Maxilliped 3 ischium 0.6 times as long as merus.

Pereopod 1 (cheliped) 4.6 times as long as carapace, merus 1.37 times as long as carapace, carpus 0.55 times as long as merus, propodus 1.6 times as long as merus, fingers 0.5 times as long as total propodus length. Merus with 1+6 spines along upper margin, 1+3 spines along mesial face, 1+14 spines along lateral face, 1+2 spines on lower margin; carpus with 1+2 spines on upper margin, 1+1 spines on mesial face, 1+2 spine on lateral face; propodus oval in cross-section, with 4 spines on upper margin, without spines along mesial face, with 1 spine on lateral face, with 1 spine on lower margin; fixed finger with 1 proximal blunt tooth and another third way along separated by concavity; dactylus with 2 proximal blunt teeth on either side of first opposing tooth.

Pereopod 2 3.3 times carapace length, merus 1.4 times carapace length, 8.3 times a long as greatest width, carpus 0.25 times as long as merus, propodus 0.5 times as long as merus, dactylus 0.8 times as long as propodus; merus with 1+9 spines along extensor margin, with 1+7 spines along flexor margin; carpus with 1+1 spines along extensor margin; dactylus sinusoidal on extensor margin, tapering over distal half, 6.2 times as long as greatest basal width, with row of 21 robust setae distal to heel of flexor margin.

Pereopod 3 3.3 times carapace length, merus 1.4 times carapace length, 7.5 times a long as greatest width, carpus 0.25 times as long as merus, propodus 0.6 times as long as merus, dactylus 0.7 times as long as propodus; merus with 1+9 spines along extensor margin, with 1+8 spines along flexor margin; carpus with 1+3 spines along extensor margin; dactylus sinusoidal on extensor margin, tapering evenly, 6.2 times as long as greatest basal width, with row of 8 robust setae distal to heel of flexor margin.

Pereopod 4 3.1 times carapace length, merus 1.1 times carapace length, 5.8 times a long as greatest width, carpus 0.4 times as long as merus, propodus 0.7 times as long as merus, dactylus 0.6 times as long as propodus; merus with 1+16 spines along extensor margin, with 1+10 spines along flexor margin, without spines on upper face; carpus with 1+3 spines along extensor margin; dactylus more evenly tapering than dactylus 2, distally less setose, 6.2 times as long as greatest basal width, with 2 robust setae distal to heel of flexor margin.

Paratype, 28 mm (AM P.90863). Telson anterolateral margin sinusoidal, concave over anterior two-thirds, with short dorsal sharp secondary ridge, anterior section ending at obtuse angle, remainder convex, obscurely crenellate.

Pereopod 1 (cheliped) of slender form, covered with flat squamae fringed with short setae; 3.6times as long as carapace, merus 1.0 times as long as carapace, carpus 0.65 times as long as merus, propodus 1.6 times as long as merus, fingers 0.54 times as long as total propodus length. Merus with 1+7 spines along upper margin, 1+4 spines along mesial face, 1+13 spines along lateral face, 1+2 spines on lower margin; carpus with 1+5 spines on upper margin, 1+4 spines on mesial face, 1+2 spines on lateral face, without spines on lower margin; propodus square in cross-section, with 0+4 spines on upper margin, with 1+3 spines mesial face, with 1+3 spines on lateral face, with 2 spines on lower margin; dactylus cutting edge with ridge of c. 50 uneven teeth, few more prominent than others; all rows of spines with intermediate smaller spines and emerging scales.

a h i

Pereopod 2 3.1 times carapace length, merus 1.15 times carapace length, 8.0 times a long as greatest width, carpus 0.25 times as long as merus, propodus 0.6 times as long as merus, dactylus 0.8 times as long as propodus; merus with 1+16 spines along extensor margin, with 1+8 spines along flexor margin; carpus with 1+1 spines along extensor margin; dactylus sinusoidal on extensor margin, tapering over distal half, 7.5 times as long as greatest basal width, with row of 22(24) robust setae distal to heel of flexor margin.

Pereopod 3 3.1 times carapace length, merus 1.1 times carapace length, 7.5 times a long as greatest width, carpus 0.25 times as long as merus, propodus 0.7 times as long as merus, dactylus 0.7 times as long as propodus; merus with 1+18 spines along extensor margin, with 1+8 spines along flexor margin; carpus with 1+3 spines along extensor margin; dactylus sinusoidal on extensor margin, tapering evenly, 7.5 times as long as greatest basal width, with row of 7 robust setae distal to heel of flexor margin.

Pereopod 4 2.9 times carapace length, merus 1.0 times carapace length, 5.6 times a long as greatest width, carpus 0.3 times as long as merus, propodus 0.8 times as long as merus, dactylus 0.6 times as long as propodus; merus with 1+17 spines along extensor margin, with 1+10 spines along flexor margin, without spines on upper face; carpus with 1+3 spines along extensor margin; dactylus more evenly tapering than dactylus 2, distally less setose, 6.6 times as long as greatest basal width, with 2 robust setae distal to heel of flexor margin.

Colour. Generally orange, spines highlighted with red-orange, sometimes white; deeper colour on margins of pereopods, deeper orange bands across distal ends of pereopodal meri, carpi, propodi and dactyli (from N. Coleman photo 471 of a specimen from 400 m off Newcastle, NSW – not found).

Variation. The long concave and shorter convex sections of the anterolateral margin of the telson are separated by a hiatus that may take the form of a short notch or obsolete step and is more obvious in larger males. While females are generally simply sinusoidal, larger ovigerous examples tend to have more pronounced denticulation than other, approaching that of males. Two of numerous specimens had one or two spines on the face of the merus of pereopod 4 but these were poorly developed compared to those in species of clade A ( Fig. 10 i).

Etymology. From Tasman Sea, the western margin of which the species inhabits, and incerta , original species in this complex.

Distribution. Eastern Australia, 18°S–33°S, 156–740 m (median 573 m) depth.

Remarks. Identification of several eastern Australian specimens initially fixed in formalin and unsuitable for molecular treatment proved initially problematic. The counts of robust setae on the dactyli of pereopods 2–4 are generally lower values than for A. indocerta to which they seemed most similar (median values 35, 17, 10). None of the preserved specimens have pereopods with the distinctive banded pattern that persists in preserved specimens of A. indocerta . Furthermore, facial spines are not present on the merus of pereopod 4 (with two aberrant exceptions) which would place them on the other of the major clades of species discovered by molecular analysis. The numbers of dactylar robust setae were similar to those of A. incerta and A. norfocerta , which, like A. tasmancerta , have no spines on the upper face of the merus of pereopod 4. But in both these species the anterolateral margin of the telson could be interpreted as 3-lobed with an upturned middle region.

Figures

FIGURE 2. Colour photographs of living animals by T. - Y. Chan unless otherwise noted. a, Agononida africerta, paratype, Mozambique, MNHN IU- 2008 - 10190; b, A. auscerta, PNG, MNHN IU- 2011 - 2426; c, A. incerta, Taiwan (from Baba et al. 2009 and Poore & Andreakis 2012); d, A. indocerta, Western Australia, D. Evans (from Jones & Morgan 2002 and Poore & Andreakis 2012); e, A. madagascerta n. sp., paratype, Madagascar, MNHN IU- 2009 - 1891; f, A. norfocerta, PNG, MNHN IU- 2011 - 891; g, A. polycerta n. sp., French Polynesia, TARASOC stn DW 3377 (specimen not located), L. Corbari; h, A. rubrizonata, paratype, Taiwan (from Poore & Andreakis 2012); i, A. tasmancerta, New South Wales (specimen not located), Image # 741 reproduced from 35 mm slide courtesy of The Neville Coleman Collection.

FIGURE 10. Agononida tasmancerta n. sp. Supermale, 25 mm, holotype, AM P. 90862: a (first row, telson and detail of anterolateral margin); b – d, dactyli of pereopods 2 – 4 with robust setae at greater scale; e, pereopod 1, upper and lateral view. Paratype, ovigerous female, 21 mm, AM. P. 90863: f (row), anterolateral margin of telson; g, pereopod 1, upper and lateral views. Female paratype, 28 mm, AM P. 90863: h, anterolateral margin of telson. Paratype, ovigerous female, 25 mm, AM P. 42262: i, ischium and base of merus of pereopod 4 (with 2 facial spines). Line drawings to same scales. Chelipeds to same scale.