Magnovis elizabethae, Alves & Lowry & Johnsson, 2020

Alves, Jessika, Lowry, James K. & Johnsson, Rodrigo, 2020, A new superfamily and family of Hadziida (Amphipoda: Senticaudata), with a description of a new genus and new species from the Brazilian continental shelf, Zootaxa 4779 (4), pp. 573-583 : 575-582

Magnovis elizabethae sp. nov.

( Figs. 1–7 )

Examined material. Holotype. Adult Male (dissected and drawn) 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), 91 m depth, Brazil, 25 June 1970, Oceanographic Ship Prof W. Besnard, dredged, UFBA 3123 . Allotype. Adult Female (dissected and drawn) 15 mm, Campos Basin (40°20’16’W, 20°19’8’’S b), 91 m depth, Brazil, 25 June 1970, Oceanographic Ship Prof W. Besnard, dredged, UFBA 3124 . Paratypes. Adult Male , 10 mm, Campos Basin (40°20’16’’W, 20°19’8’S), 91 m depth, Brazil, 25 June 1970, Oceanographic Ship Prof W. Besnard, dredged, UFBA 3125 . 2 Adult Female (dissected) 14 and 16 mm, Campos Basin (40°20’16’W, 20°19’8’’S), 91 m depth, Brazil, 25 June 1970, Oceanographic Ship Prof W. Besnard, dredged, UFBA 3126 .

Type Locality. 40°20’16’’W, 20°19’8’S, Campos Basin , Rio de Janeiro State, Brazil .

Etymology. The type species name is in honor of Dr. Elizabeth Neves (UFBA), who has been dedicated during her career to training new Brazilian taxonomists and to improving the knowledge of invertebrate biodiversity from Brazil.

Description. (Based on holotype, male, 12 mm). Head. Antenna 1 shorter than peduncle of antenna 2; article 2 inflated; accessory flagellum 2-articulated as long as the third peduncle article; peduncle longer than flagellum; flagellum with 9 articles. Antenna 2 scarcely setose; article 1 not bulbous; article 2 cone gland with a row of setae, not reaching the end of article 3; article 4 lightly longer than article 5; flagellum with 10 articles. Head lateral cephalic lobe broad and rounded, eyes absent, anteroventral margin rounded and smooth ( Fig. 2 ).

Mouthparts. Mandible, molar produced and well developed, dominating mandible, triturative, with a plumose setae on left mandible; accessory setae row with 8 simple slender setae; left and right incisor 3-dentate; right and left lacinia mobilis 4 and 3 dentate, respectively; palp article 1 about 3 times shorter than article 2, with an acute produced apical corner; article 2 about 4 times longer than wide, longer and broader than article 3, article 3 slender with long lateral and apical setae. Maxilla 1, palp 2-articulate; article 1 less than 30% the length of article 2; article 2 apically broad, rounded with stout setae; outer plate with apical pectinate setae; inner plate subtriangular with two long apical plumose setae, inner and outer margin with small setae. Maxilla 2, outer plate slender with long apical setae, inner plate 80% the length of the outer one, beset with long plumose setae. Maxilliped palp slender, 4-articulate, article 1 subquadrate, article 2 about 2 times longer than article 3, with long slender setae on lateral margins, facial margin with little slender setules, article 4 reduced; outer plate falcate, big and densely setose, facial margin with little setae; inner plate apically truncated with slender plumose setae. Lower lip, outer plate expanded laterally; outer and inner plate with apical sparse setae ( Fig. 3 ).

Pereon. Gnathopod 1 subchelate, coxa, anteroventral corner produced and subacute; basis long and large, about 2.4 times longer than wide, with several long and slender setae; merus reduced, similar in length to ischium, about 0.4 times the basis length, posteroventral corner with slender setae; ischium subrectangular, posteroventral corner not pronounced, posterior margin setose; carpus well developed 1.5 times longer than wide, about 0.3 times longer than propodus, posterior margin densely setose, anterior margin acutely expanded; propodus subrounded, with anterior and posterior margin with long slender setae, palm subrounded, smooth; dactylus as long as palm, smooth, outer margin without setae ( Fig. 4 ).

Gnathopod 2 subchelate, coxa subquadrate, ventrally excavated; basis posterior margin with sparse long setae, anteroventral corner with a set of long setae; ischium posteroventral corner with two simple setae; merus 0.5 times longer than ischium, ventral margin accentually convex, posteroventral corner produced and acute with a long setae; carpus subtriangular, shorter than propodus, anterodorsal corner very expanded and acute, posterior dorsal corner rounded; posterior margin rounded; propodus well developed, longer than carpus, 1.5 times longer than wide, with long posterior setae and small ventral setae; palm acute, strongly serrate, palmar corner defined by a small spine, anterior margin with long and small setae; dactylus curved, naked, reaching the palmar corner ( Fig. 4 ).

Pereopod 3, coxa rounded, basis slender, posterior margin with many small setae; merus slender, about 0.7 times longer than carpus; carpus and propodus subequal in length, reduced and covered by long setae; dactylus small, dactylar unguis with a small seta ( Fig. 4 ). Pereopod 4 similar to pereopod 3, except by the posterodorsal notch in coxa 4 ( Fig. 4 ).

Pereopod 5, coxa with an anteroventral lobe rounded; basis ovate, slender, posterior margin undulated with 4 long setae; merus well developed, about 0.7 times longer than carpus; carpus 0.2 times longer than propodus, setose in lateral margin; propodus reduced and thin, beset with slender setae; dactylus small, dactylar unguis with a small setae ( Fig. 5 ). Pereopod 6, coxa with an anteroventral lobe rounded; basis slender, posterior margin smooth with 7 stout setae; merus longer than carpus, about 0.3 times; carpus wider than propodus, with stout setae on posterior and anterior margin; propodus lightly longer than carpus, densely setose; dactylus reduced, dactylar unguis present, with a small setae ( Fig. 5 ). Pereopod 7 basis slender, anterior margin with stout setae, posterior margin with 3 long and 6 small setae, posteroventral corner slightly serrated; merus subequal in length to carpus with scarce small setae; carpus subrectangular about 0.6 times longer than propodus, setose and thin, propodus 0.2 times thinner than carpus, with a dense row of anterior setae; dactylus slender, long, dactylar unguis present with one slender seta ( Fig. 5 ).

Pleon. Epimeral plates. Epimeral plate 1 posteroventral corner acute, slightly produced; ventral margin smooth with small slender setae. Epimeral pate 2 posteroventral corner rounded and smooth. Epimeral plate 3 posterior margin rounded and serrated, posteroventral corner rounded, ventral margin smooth with small slender setae ( Fig. 2 ).

Urosome. Uropod 1 peduncle subequal in length to rami, 2 basofacial setae present, stout and robust, lateral margin with long, well-developed setae, distal spur present; rami slender subequal in length, with dorsal and apical slender and long setae ( Fig. 5 ). Uropod 2 peduncle sub-rectangular, 0.75 times the length of the rami; rami long, slender subequal in length with lateral small and slender setae ( Fig. 5 ). Uropod 3, peduncle subrounded, 0.3 times the length of the rami; rami foliaceous with a dense fringe of long slender setae on the dorsal and distal margins; endopod 90% the length of outer; exopod with a soft basolateral undulation ( Fig. 5 ). Telson deeply cleft (about 72%), thin, tapering distally, 0.25 times longer than wide, apically truncate with cusp and two apical setae in each lobe ( Fig. 5 ).

Sexual dimorphic characteristics. Based on the allotype female, 16 mm ( Fig. 7 ). Gnathopod 1 of female slenderer than male, basis posteroventral corner with a row of long setae; merus posteroventral corner acute, posterior margin setose; carpus 0.25 times longer than propodus, anterior and posterior margin setose, anteroventral corner rounded and less expanded than male; propodus subrounded, setose, palm rounded to straight; dactylus similar to males, reaching the end of palm ( Fig. 6 ). Gnathopod 2 coxa subquadrate, ventral margin beset with setae; basis and merus less setose than males; carpus subtriangular, shorter than propodus, posterior and anterior margin with a row of slender setae; propodus subovate, narrowing in distal margin, palm rounded, slightly undulated, palm not defined; dactylus smooth, without setae ( Fig. 6 ). Uropod 3 of females thinner than males, but similar in shape ( Fig. 6 ). Telson cleft, about 70%, with two apical setae each lobe ( Fig. 6 ).

Figures

FIGURE 1. Magnovis elizabethae sp. nov.; Holotype, male 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3123. Scale bars: 1.0 mm.

FIGURE 2. Magnovis elizabethae sp. nov.; Holotype, male 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3123. Scale bars: 0.5 mm.

FIGURE 3. Magnovis elizabethae sp. nov.; Holotype, male 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3123. Scale bars: 0.3 mm.

FIGURE 4. Magnovis elizabethae sp. nov.; Holotype, male 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3123. Scale bars: G1–2 (1 mm); P3–4 (0.5 mm).

FIGURE 5. Magnovis elizabethae sp. nov.; Holotype, male 12 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3123. Scale bars: P5–7 (1 mm), U1–3, T(0.5 mm).

FIGURE 6. Magnovis elizabethae sp. nov.; Allotype: female 15 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA 3124. Scale bars: G1–2 (1 mm); U1, T(0.5 mm).

FIGURE 7. Magnovis elizabethae sp. nov.; Allotype: female 15 mm, Campos Basin (40°20’16’’W, 20°19’8’’S), MBT 180, Campos Basin, Brazil, UFBA3124. Scale bars: 1.0 mm