Iphiplateia jakei, Coleman, Oliver & Lowry, James K., 2012

Coleman, Oliver & Lowry, James K., 2012, Revision of the genus Iphiplateia (Crustacea, Amphipoda, Phliantidae) from Australia, Zootaxa 3393, pp. 1-26 : 15-20

Iphiplateia jakei sp. nov.

( Figs 9–12)

Type material studied. Holotype, male?, 4 mm. NMV J 20887 .

Type locality. Port Phillip Bay, Point Lonsdale, Pier, Victoria, Australia, (38°18'S 144°37'E), 1 m depth; red and green algae, hand/snorkel, leg. G.C.B. Poore, 25 February 1991, Stn CRUST 106.

Additional material examined. 1 male, 2.1 mm, NMV J 59358 , Western Port, off Crib Point, Victoria, Australia (38°19'59''S 145°15'08''E), FV Melita, 2 m depth, leg. A.J. Gilmor, Smith-McIntyre grab, 16 March 1965, CPBS-N 12; 1 specimen, unknown sex, 2.2 mm, NMV J 60904 , 2 km SE of Point Nepean; Victoria, Australia (38°19'49''S 144°39'56''E), 12 m depth, leg. T.D. O'Hara & S.P. Heislers, airlift, 17 May 1996, VNPMS 89 4; 1 specimen, unknown sex, 2.2 mm, NMV J 59359 , Western Port, off Crib Point, Victoria, Australia (38°22'17''S 145°13'25''E), FV Melita, 3 m depth, leg. A.J. Gilmor, Smith-McIntyre grab, 16 March 1965, CPBS-N 02; 1 juvenile, 1.1 mm, NMV J 59352 , Nepean Bay, Point Nepean,Victoria, Australia (38°18'24''S 144°39'28''E), 5–6 m depth; leg. T.D. O' Hara & Plummer, Quadrat/ SCUBA, 8 April 1998 – 25 May 1998, WV 8.

Etymology. This species is named for Jake Willcox, the dear son in law of the senior author.

Description. Based on male? holotype, 4 mm. Body shape ( Fig. 9a) oval from above, coxal plates splayed very much, body flat, with a dorsal carina ( Fig. 9a, h). Pereonite 1 longest. Pleonite 1 pointed posteriorly.

Head shorter than coxal plate 1 which partly cover the lateral sides of the head; eyes small, rounded; rostrum wide, rounded. Antenna 1 ( Fig. 9b) peduncular article 1 with distal rounded lobe medially, less than half as wide as the maximum article width; article 2 with a similar lobe, but with a convex outer margin, its apex reaches the distal margin of peduncular article 3; flagellum 4-articulate, apical article very narrow. Antenna 2 ( Fig. 9c) peduncular articles 4 and 5 weakly widened distally; flagellum of 4 articles. Upper lip ( Fig. 9g) wide, rectangular, truncate distally. Mandible ( Fig. 9d, e) incisors dentate; raker row consisting of small spines; molar just a narrow protrusion, not triturative; no palp present. Maxilla 1 ( Fig. 10a) inner plate missing (?), outer plate with 5 apical robust serrate setae, no palp present. Maxilla 2 ( Fig. 10b) inner plate twice as wide than outer plate with a row of few short stout setae apicomarginally. Maxilliped ( Fig. 10c) inner plate apically truncate, with nodular setae distally; outer plate wide and rounded with few setae mediomarginally; palp 4-articulate, article 2 medially slightly produced with long slender setae, article 3 as wide as article 2, article 4 weakly curved medially.

Pereon. Pereopod 1 ( Fig. 10d, e) coxa anterodistally expanded; basis expanded posteromarginally; ischium and merus subequal in length; merus and carpus connected by oblique articulation; carpus slightly shorter than propodus, anterodistal margin of carpus with a row of stout setae; propodus with an anteroproximal group of scattered stout setae; dactylus falcate. Pereopod 2 ( Fig. 11a) coxa subrectangular, somewhat expanded posterodistally; a b c

d e f g

h b

a

c d e a

b c e d

200

f a

b c

d e f basis to dactylus similar in shape as in pereopod 1, but without the medial stout setae on carpus and propodus. Pereo pod 3 ( Fig. 11b) coxa subrectangular, slightly drawn out posterodistally; basis expanded posteromarginally; ischium slightly longer than merus; merus distally expanded and anterodistal corner drawn out; carpus as long as merus; propodus 1.75 x carpus length; dactylus falcate. Pereopod 4 ( Fig. 11d) coxa longer than wide, posteroproximally excavate; basis to dactylus as in pereopod 3. Pereopod 5 ( Fig. 12a) coxa wider than long, bilobate, anterior lobe much larger as posterior lobe; basis long and strongly expanded posteriorly, with a wide lobe ventrally; ischium wider than long, slightly produced anterodistally; merus very wide, drawn out antero- and posterodistally and excavate distally; carpus ovoid with distomarginal lobe; propodus about as long as width of merus, with an anterodistomarginal spine; dactylus falcate. Pereopod 6 ( Fig. 12b) similar to pereopod 5, but coxa smaller and basis not as wide. Pereopod 7 ( Fig. 12c) coxa small, weakly bilobed, posterior lobe much smaller than anterior one; basis large with a very wide posterior lobe, strongly expanded ventrally; ischium to dactylus subequal to those of pereopods 5 and 6.

Pleon. Pleopod 1 ( Fig. 11c) peduncle subrectangular, shorter than inner ramus, with 6 coupling hooks; outer ramus slightly longer than inner. Pleopod 2 ( Fig. 11f) peduncle as wide as long, expanded medially, with 6 coupling hooks; outer ramus 1.2 x as long as inner ramus; inner ramus longer than peduncle. Pleopod 3 ( Fig. 11e) peduncle very short, with a long narrow medial lobe, at its end 5 coupling hooks; inner ramus small; outer ramus long. Uropod 1 ( Fig. 12e) about 1.6 x as long as uropod 2; outer ramus slightly shorter than peduncle, inner ramus 65% of outer. Uropod 2 ( Fig. 12f) inner ramus 60% of peduncle length; outer ramus 1.2 x as long as inner ramus. Uropod 3 ( Fig. 12d) peduncle wide and largely hidden by telson; inner ramus wanting, outer ramus slender. Telson wider as long, apically rounded.

Variability. There is some variability in the height of the dorsal keel and the length of the coxal plates.

Remarks. For differences between I. jakei sp. nov. and the similar I. verenaae sp. nov. see Table 2 .

Distribution. Victoria, Australia.

Tables

TABLE 2. Morphological differences between Iphiplateia jakei sp. nov. and Iphiplateia verenaae sp. nov..

character	I. jakei sp. nov.	I. verenaae sp. nov.
A1 peduncle article 1	with short distolateral lobe, flat	distolateral lobe almost as long as disto medial lobe, folded dorsally
A1 peduncle article 2	with medial lobe only, which reaches distal margin of 3rd article	with medial lobe, shorter than distal margin of 3rd article and additional dorsolateral lobe
Pereopod 5–6 carpus:merus width	68–70%	55–62 %
Pereopod 7 carpus:merus width	55%	80%
Pereopod 7 basis	wider than basis of pereopods 5–6	narrower than basis of pereopods 5–6