Kapalana durraween, Berents & Lowry, 2018

Berents, Penelope B. & Lowry, J. K., 2018, The New Crustacean Amphipod Genus Kapalana from Australian Waters (Senticaudata, Ischyroceridae, Ischyrocerinae, Cerapodini), Records of the Australian Museum 70 (4), pp. 391-421 : 397-398

Kapalana durraween sp. nov.

Figs 4–6

Holotype, male, 9.4 mm, AM P.21868, off Disaster BaY , New South Wales, Australia (37°16'S 150°5'E), 91 m, K. Moller, May 1930 . Paratypes: 1 male, 6.9 mm, AM P.10721, off Twofold Bay , New South Wales, Australia (37°5'S 150°9'E), 82 m, K. Moller on Durraween, August 1929 ; 1 male, 8.2 mm, AM P.76108 ; 1 female, 7.0 mm, AM P.76109 ; 4 males, 1 female, AM P.10719, off Twofold BaY , New South Wales, Australia (37°5'S 150°7'E), 82 m, K. Moller on Durraween, July 1929 .

Additional material examined. 10 specimens, AM P.21867, 35 km east of Port Jackson , New South Wales, Australia (33°50'S 151°40'E), 366 m, 27 March 1905 ; 1 female, AM P.10720, west-south-west of Gabo Island , Victoria, Australia (37°34'S 149°55'E), 128 m, K. Moller on Durraween, December 1929 ; 1 female, 2 juveniles, AM P.76107, off Disaster Bay , New South Wales, Australia (37°16'S 150°5'E), 91 m K. Moller, May 1930 .

Etymology. Named for the trawler Durraween, whose Master, Captain K. Moller, contributed many natural history specimens to the Australian Museum. Used as a noun in apposition.

Description. Based on Holotype, male 9.4 mm,AM P.21868.

Head. Rostrum long, length 0.3 × head, evenly tapered, apically acute; lateral cephalic lobe with ventral corner rounded, subocular margin deeply recessed, reaching beyond eye, anteroventral corner rounded, ventral margin horizontal, posterior margin sloping. Antenna 1 very long, length 0.8 × body length; peduncle with scales; peduncular article 1 shorter than article 3, length 0.7 × peduncular article 3, not produced anterodistally and anteromedially, with strong sub-quadrate projection along posterior margin, posterodistal corner not produced; peduncular article 2 anterodistal corner with distal projection flagellum10-articulate; article 1 short. Antenna 2 length equal to antenna 1; flagellum 9-articulate. Epistome and upper lip fused, produced, broad base, apically acute.

Pereon. Pereonite 1 with lateral keel, without sternal keel. Pereonites 2–3 with sternal keel. Pereonite 5 length 1.4 × depth.

Gnathopod 1 subchelate; coxa not fused to pereonite 1, without anteroventral lobe; basis length 2.1 × depth; carpus broad, length 1.5 × depth with setose posterior lobe, propodus palm acute, robust setae absent. Gnathopod 2 carpochelate; coxa not fused to pereonite 2, length 1.6 × depth, without anteroventral lobe or cusp; basis short, broad, length 1.4 × breadth, basis without anteroproximal group of long slender setae, basis without anteroproximal bulge; carpus long, length 1.2 × breadth, broad, palm shallowly excavate, anterodistal tooth large, located near articulation with propodus, posterodistal tooth well defined, medium length, length 1.2 × width; propodus broad, curved, length 4.5 × width, without tooth on posterior margin, posterodistal corner smooth, without spines; dactylus length 0.4 × propodus.

Pereopod 3 coxa not fused to pereonite 3, with broad anteroventral lobe, length 1.9 × depth; basis, length 1.9 × breadth, with proximal, subquadrate anterodorsal corner, with plumose setal group and simple setae along anterior margin, without denticles along anterior margin; ischium long, length 2 × breadth; merus length 1.1 × breadth; short; without ridges. Pereopod 4 coxa not fused to pereonite 4, length 2.1 × depth, with anteroventral lobe; basis length 1.7 × breadth, with plumose setal group midway along anterior margin or with simple setae along entire anterior margin; ischium long, length 2.5 × breadth; merus long, length 1.4 × breadth. Pereopod 5 coxa length 1.2 × depth, without patches of small setae, with setae along ventral margin few or absent; merus with anterior lobe extending beyond anterior margin of carpus, posterior lobe with 6 plumose setae; propodus with 4 setae along posterior margin; dactylus short, uncinate with 2 accessory hooks. Pereopod 6 coxa with setal fringe ventrally, without patches of small setae near margins; basis without patch of small setae near anterior margin; merus length 1.6 × breadth; dactylus short, uncinate, with 2 accessory hooks. Pereopod 7 coxa without posterodorsal lobe; merus length 2.1 × breadth; dactylus short, uncinate, with 2 accessory hooks.

Pleon. Pleopods 1–3 biramous, decreasing in size anteroposteriorly. Pleopod 1 inner ramus 9-articulate; outer ramus 9-articulate, article 1 evenly swollen. Pleopod 2 inner ramus reduced, 1-articulate; outer ramus, broad, 1-articulate. Pleopod 3 inner ramus reduced, 1-articulate; outer ramus broad, 1-articulate. Uropod 1 biramous; peduncle, length 1.4 × outer ramus; rami with distoventral fan of robust setae; outer ramus with lateral row of denticles, without medial setae, with 14 lateral setae, with large apical robust seta and smaller slender setae; inner ramus length 0.5 × outer ramus, with 1 medial, and 3 lateral setae, without large apical robust seta. Uropod 2 uniramous, peduncle, length 2.8 × breadth, 4.4 × length of ramus; ramus small with 7 denticles and 1 slender apical seta. Uropod 3 uniramous, peduncle length 1.5 × breadth; ramus with 2 curved hooks. Telson length 0.6 × breadth, moderately cleft (58%), each lobe with 26–30 anteriorly directed hooks in 2 rows.

Female (sexually dimorphic characters). Based on paratype female 7.0 mm, AM P.76109. Antenna 1 flagellum 9-articulate. Pereonite 1 without lateral keel. Pereonites 2–3 without sternal keel. Pereonite 5, length 1.9 × depth. Gnathopod 1 coxa, length 1.1 × depth; basis, length 2 × depth; carpus length 1.3 × depth with setose posterior lobe. Gnathopod 2 subchelate; coxa, length 1.7 × depth; basis, length 2.2 × breadth. Pereopod 5, coxa, length 1.4 × depth. Oostegites from gnathopod 2 to pereopod 5.

Tube. Tubes of juveniles attached in a ring, circling the tube of adult female.

Habitat. Continental shelf and slope (82–366 m depth). Remarks. The shape of gnathopod 2 propodus and carpus changes as males grow, with the carpus becoming longer than wide and the propodus becoming curved and slender in large males. In males less than 7 mm, the length and breadth of the carpus are equal and the propodus is less than three times as long as wide

Three species, K. amelga , K. durraween and K. maia , have an evenly tapered rostrum. Neither Kapalana durraween nor K. maia have a large apical seta on the inner ramus of uropod 1. Kapalana durraween differs from K. maia in having scales on the peduncle of antenna 1, a lateral keel on pereonite 1 and a sternal keel on pereonite 3.

35 km east of Port Jackson, New South Wales, Australia (diameter of central tube = 2mm).

Distribution. Australia. New South Wales: east of Port Jackson; off Twofold BaY; off Disaster BaY. Victoria: west south west of Gabo Island.

Figures

Figure 4. Kapalana durraween sp. nov.,AM P.21867, central maternal tube with encircling juvenile tubes,

Figure 5. Kapalana durraween sp. nov., holotype, male, 9.4 mm, AM P.21868; paratype, female, 6.96 mm, AM P.76109; paratype male “a”, 6.9 mm, AM P.10721; Disaster Bay, New South Wales, Australia. Gnathopod 2 male “a” and pleopods 1–3 insertion points of setae are indicated by small circles. Scales represent 0.1 mm.

Figure 6. Kapalana durraween sp. nov., holotype, male, 9.4 mm, AM P.21868; paratype, female, 6.9 mm, AM P.76109; Disaster Bay, New South Wales, Australia. Scales represent 0.1 mm.