Iphimedia magellanica Watling & Holman 1980

“Iphimedia magellanica n. sp.

Material.—Holotype. Eltanin Cruise 11, Sta. 977, 13 Feb. 1964, 52°32'S, 63°53'W, 299 m, 1 ♀ with eggs (USNM 173584), 6 mm. Paratypes: same station, 4 juveniles (USNM 173585).

Diagnosis.—Body with short, paired dorsal processes on pereonite 7 and pleonites 1 and 2; pleonites 1-3 with mid-dorsal keel; pereopod 7 basis posterior margin with 3 teeth, coxa with single posterodistal tooth.

Description.—Body with 3 pairs dorsal processes, all short and somewhat curved downward; pleonites 1 and 2 with short mid-dorsal keel; pleonite 3 mid-dorsal keel enlarged. Pleurae on pereopods 5-7 extend as posteriorly-directed acute processes. Epimeral plates 1 and 2 with small posterodistal tooth. Hind margin of epimeral plate 3 with 2 teeth. Head lateral margin slightly produced as acute process distally; rostrum extends nearly length of first peduncle article of antenna 1. Ventral tooth of antenna 1 peduncle article 1 extends to end of peduncle article 2, dorsal tooth small. Antenna 2 peduncle article 3 with short lateral and dorsal apical teeth. Upper lip broadly rounded, with paired ventrolateral groups of fine setae. Left man­dible with blunt, smooth incisor, accessory plate weakly toothed; right man­dible without accessory tooth; palp article 2 twice length of article 3, armed with only 2 distal setae; third palp article with setae on ventral margin of distal third of article. Lower lip variably incised. Maxilla 1 palp biarticulate, not reaching end of outer plate; inner plate small, with 5 long setae; outer plate with 11 stout setae apically. Maxilla 2 slender, inner and outer plates subequal in width; distal setae on outer plate only slightly longer than on inner plate. Maxilliped palp 3-articulate, article 2 produced medially along article 3, article 1 longer than article 2, third article elongate, distally blunt, two-thirds the length of article 2; inner plate narrow, armed with plumose setae along distal half of inner margin; outer plate apically subacute.

Gnathopod 1 chelate; coxa distally subacute, with 4 short setae; basis with scattered short setae along inner margin; dactyl equal in size to fixed finger of propodus, with 2 long, blunt setae; propodus fixed finger with 4 long setae, 2 of which are distally forked. Gnathopod 2 chelate; coxa distally quadrate; article 6 longer than article 5. Pereopods 5-7, basis posterior margin with 3 teeth, 1 located dorsally and 2 ventrally. Uropod 1 rami subequal; uropod 2 outer ramus shorter than inner. Telson shallowly cleft.

Etymology.—Name derived from Magellanic zoogeographic province.

Distribution.—Known only from locality listed above.

Remarks.—This species is distinctive among species of Iphimedia in its possession of only 3 pairs of short, downwardly curving dorsal processes and single, upright keel on pleonite 3 in combination with the form of the posterior pereopods and coxae. The general body form suggests affinities with I. multidentata and I. macrocystidis; however the absence of paired posterior teeth on coxa 7 and the number of teeth on pereopod 7 basis hind margin readily distinguish I. magellanica from both species.”

(Watling & Holman, 1980: 619-621)