Kapalana amelga, 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 : 393-395

Kapalana amelga sp. nov.

Figs 1–3

Holotype, male, 8.8 mm, AM P.99050, south-west side of Grasshopper Island , New South Wales, Australia (35°38'01"S 150°19'51"E), hand collected on scuba, in the red alga Peyssonnelia novaeholliandiae , 11 m, P. B. Berents, J. Eu, A. J. Millar & G. D. F. Wilson on RV Baragula, 10 February 2003, Hermon Slade Batemans Bay Expedition, NSW 2038 . Paratype female, 6.5 mm, AM P.99051, type locality, hand collected on scuba in the red alga Amphiroa anceps , 13 m, P. B. Berents, J. Eu, A. J. Millar & G. D. F. Wilson on RV Baragula , Hermon Slade Batemans Bay Expedition, 9 February 2003, NSW 2034 .

Additional material examined. One female, 3 juveniles, AM P.99052, type locality, hand collected on scuba in red alga Peyssonnelia novaeholliandiae , 11 m, P. B. Berents, J. Eu, A. J. Millar & G. D. F. Wilson on RV Baragula, 10 February 2003, Hermon Slade Batemans Bay Expedition ,

NSW 2038; 1 male, 1 female, 8 juveniles, AM P.99053, type locality, hand collected on scuba in red alga Amphiroa anceps , 13 m, P. B. Berents, J. Eu, A. J. Millar & G. D. F. Wilson on RV Baragula , 9 February 2003, Hermon Slade Batemans Bay Expedition, NSW 2034 ; 2 males, 3 females, 1 juvenile, AM P.99054, type locality, hand collected on scuba in red alga Amphiroa anceps , 13 m, P. B. Berents, J. Eu, A. J. Millar & G. D. F. Wilson on RV Baragula , 9 February 2003, Hermon Slade Batemans Bay Expedition, NSW 2034 .

Type locality. South-west side of Grasshopper Island, New South Wales, Australia (35°38'01"S 150°19'51"E) .

Etymology. From the Spanish word amelga , meaning a ridge between two furrows and referring to the ridged posterior margin on the propodus of gnathopod 2.

Description. Based on Holotype, male, 8.8 mm, AM P.99050.

Head. Rostrum long, length 0.4 × head, evenly tapered, apically acute; lateral cephalic lobe with ventral corner subacute, subocular margin deeply recessed, reaching beyond eye, anteroventral corner subquadrate, ventral margin horizontal, posterior margin vertical. Antenna 1 long, length 0.5 × body length; peduncle with scales; peduncular article 1 longer than article 3, length 1.2 × 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 without distal projection; flagellum 8-articulate; article 1 short. Antenna 2 length equal to antenna 1; flagellum 7-articulate.

Epistome and upper lip fused, produced, broad base, apically subquadrate.

Pereon. Pereonite 1 with lateral keel, without sternal keel. Pereonites 2–3 with sternal keel. Pereonite 5 length 1.6 × depth.

Gnathopod 1 coxa not fused to pereonite 1, length 1.1 × depth, without anteroventral lobe; basis length 2.5 × depth; carpus broad, length 1.4 × 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 1.9 × breadth, without anteroproximal group of long slender setae; carpus long, length 1.3 × breadth, broad, posterior margin with row of small spines, palm shallowly excavate, anterodistal tooth large, located near articulation with propodus, posterodistal tooth well defined, medium length, length 1.1 × width; propodus slender, curved, length 4.5 × width, without tooth on posterior margin, posterodistal corner smooth, with 1 tooth; dactylus length 0.5 × propodus.

Pereopod 3 coxa not fused to pereonite 3; basis length 2.2 × breadth, evenly rounded, with simple setae along anterior margin, without denticles along anterior margin; ischium long, length 2.2 × breadth; merus length 1.1 × breadth; short; without ridges. Pereopod 4 coxa not fused to pereonite 4, with anterior lobe separated from an anteroventral lobe; basis length 1.6 × breadth, with simple setae along entire anterior margin; ischium long, length 2.4 × breadth; merus long, length 1.6 × breadth. Pereopod 5 coxa length 1.5 × 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 5 plumose setae; propodus with 2 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 with 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, without patch of small setae; merus length 1.4 × breadth; dactylus short, uncinate, with 2 accessory hooks.

Pleon. Pleopods 1–3 biramous, decreasing in size anteroposteriorly. Pleopod 1 inner ramus 8-articulate; outer ramus 6-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 1.1 × outer ramus; rami with distoventral fan of robust setae; outer ramus with lateral row of denticles, without medial setae, with 5 lateral setae, with large apical robust seta, without smaller slender setae; inner ramus length 0.5 × outer ramus, with 4–5 medial and no lateral setae, with large apical robust seta. Uropod 2 uniramous, peduncle, length 2.6 × breadth, 3.8 × length of ramus; ramus small with 3 denticles and 1 slender apical seta. Uropod 3 uniramous, peduncle length 1.9 × breadth; ramus with 2 curved hooks. Telson length 0.5 × breadth, weakly cleft (28 %), each lobe with 22–24 anteriorly directed hooks in 2 rows.

Female (sexually dimorphic characters). Based on paratype female, 6.5 mm, AM P.99051. Antenna 1 peduncle without scales; flagellum 6-articulate. Antenna 2 flagellum 6-articulate. Pereonite 1 without lateral keel. Pereonite 2–3 without sternal keel. Pereonite 5, length 2.2 × depth. Gnathopod 1 coxa, length 1.3 × depth; basis, length 2.6 × depth; carpus length 1.6 × depth with setose posterior lobe. Gnathopod 2 subchelate; palm extremely acute. Pereopod 5 coxa, length 1.3 × depth. Oostegites from gnathopod 2 to pereopod 5.

Tube. Encrusted with detritus; tubes of juveniles attached in a ring, circling the tube of adult female.

Habitat. Sublittoral (11–13 m depth).

Remarks. Kapalana amelga , like K. flindersi and K. maia , lacks scales on the peduncles of antennae 1 and 2. It differs from other species in the genus in having the posterior margin of the gnathopod 2 carpus with a row of small spines and three apical denticles on the ramus of uropod 2.

Distribution. Australia. New South Wales: Grasshopper Island.

Figures

Figure 1. Kapalana amelga sp. nov., holotype, male, 8.8 mm, AM P.99050, Grasshopper Island, New South Wales, Australia.

Figure 2. Kapalana amelga sp. nov., holotype, male, 8.8 mm,AM P.99050, Grasshopper Island, New South Wales,Australia.A1 and A2 scales, represent 0.5 mm; pleopods and urosome, scales represent 0.2 mm.

Figure 3. Kapalana amelga sp. nov., holotype, male, 8.8 mm, AM P.99050, Grasshopper Island, New South Wales, Australia. Scales represent 0.2 mm.