Quadrimaera miramirandella Alves & Neves & Johnsson 2018, sp. nov.
Creators: name: Alves, Jessika
name: Neves, Elizabeth
name: Johnsson, Rodrigo
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Melitidae
Quadrimaera
Quadrimaera miramirandella

description: Quadrimaera miramirandella sp. nov.
(Figures 7–14)
Examined material. Holotype. Adult male (UFBA 3320), 4.7 mm. Allotype. Female (UFBA 3321), 4.2 mm. Both sampled at Dois Coqueiros Beach, Ceará State, Brazil, (3°41'35.6"S; 38°35'51.1"W), associated with arenite reefs, intertidal zone (0.5 m of depth). February 2014, ALVES, J. Coll.
Type locality. Dois Coqueiros Beach, Ceará State, Brazil (3°41'35.6"S; 38°35'51.1"W).
Etymology. The new species name refers to Q. miranda and Q. mirandella, denoting a complex mixture of characteristics from both species.
Diagnosis. Light green specimens with red stains on gnathopod 2 (Fig 8). Ovigerous females carrying red eggs. Antenna 1 accessory flagellum with 7 articles. Antenna 2 cone gland not reaching the end of article 3 (Fig 10). Eyes rounded (Fig 9). Coxa 1 anteroventral corner rounded produced (Fig 12). Gnathopod 1 carpus longer than propodus, posterior margin with plumose setae (Fig 12). Gnathopod 2 propodus palm with medial excavation and molar shaped hump, dactyl inner margin acutely produced (Fig 11). Telson deeply cleft (about 70%) telsonic lobes truncate with 5 stout setae longer than telson (Fig 14).
Description. Head without notch, ocular lobe broad, rounded eyes (Fig 10). Antenna 1 scarcely setose, peduncle article 1 with slender setae; peduncle article 2 0.2 times longer than article 1, with slender setae; peduncle article 3 0.4 times the length of article 2; primary flagellum 14-articulated; accessory flagellum 7-articulated (Fig 10). Antenna 2 setose, 0.7 times shorter than antenna 1, cone gland not reaching the end of article 3, peduncular article 4 subequal in length to article 5; flagellum with 7-articulated (Fig 10).
Right mandible, palp 3-articulated, ratio of articles: 0.3:0.6:0.8; article 1 subrectangular; article 2 with 3 slender setae; article 3 with 2 lateral slender setae and 2 distal setae as long as the length of the third article (Fig 11). Maxilla 1 inner plate conical, with 2 apical setae; outer plate with 5 pectinate setae; palp 2-articulated, article 1 0.6 times shorter than article 2 which bears 7 simple setae (Fig 11). Maxilla 2 with inner and outer plates distally setose, outer plate with some pectinate setae (Fig 11). Maxilliped with inner plate quadrate bearing 8 slender distal setae; outer plate suboval, distal and inner margins with long setae; palp 4-articulated, article 2 with 3 distal simple setae, article 3 with 9 long lateral setae, article 4 with 1 apical setae (Fig 11). Lower lip, inner lobes ovate, with minute apical setae; outer lobes laterally expanded with minute apical setae (Fig 11).
Gnathopod 1 with anteroventral corner of coxa 1 rounded, ventral margin with setae; basis strong, anterior margin with 4 setae; ischium subequal in length to merus; merus with row of simple setae posteriorly; carpus laterally expanded and densely setose, with posterior row of dense setae and 2 rows of facial setae, ventral corner with row of medium setae anteriorly; propodus about 0.2 times shorter than carpus, not facially setose, posterior and anterior margins with 3 rows of setae; dactyl with inner setae (Fig 12).
Gnathopod 2 with coxa 2 bearing 5 setae on ventral margin; basis robust, posterior margin with single seta; ischium shorter than merus; carpus reduced, boomerang-shaped, with small setae; propodus greatly enlarged, anterior margin with slender setae, palm with U-shaped, medial excavation, preceded by truncated process and proceeded by sinuous excavation, palm defined by an acute and pronounced spine, preceded by a V-shaped excavation; dactylus robust, inner margin with acute process (Fig 12).
Pereopods 3–4 with slender basis, about 4 times longer than large; merus subequal in length to carpus; propodus posterior margin with setae; dacylus bifid showing a dactylar ungue (Fig 13). Pereopod 5, coxa 5 with anteroventral corner acutely produced; posterior margin of basis undulate, with 5 slender setae, posteroventral corner not produced, anteroventral corner with 2 setae; merus robust, posteroventral corner produced with a bunch of long setae; carpus about 0.6 times shorter than merus, posteroventral corner with a wisp of long setae; propodus as long as carpus, setose, posteroventral corner with a wisp of setae; dactylus bifid (Fig 13). Pereopod 6 longer than pereopod 5, posterior margin of basis with 5 small setae, posteroventral corner subquadrate; merus robust, posterior margin with 3 setae, posteroventral corner produced with abunch of long setae; carpus subquadrate; about 0,4 times shorter than merus; propodus slightly shorter than merus, posteroventral corner with a wisp of setae; dactylus bifid (Fig 13). Pereopod 7 longer than pereopod 6, basis with posterior margin smooth, posteroventral corner not produced; merus robust, posterior margin with 4 sets of setae, posteroventral corner truncate and produced, with a set of long setae, anterior margin with 5 sets of setae; carpus subequal in length to propodus, posteroventral corner with a wisp of long setae; propodus setose; dactylus bifid (Fig 13).
Epimeral plate 1 with posteroventral corner produced and acute, posterior margin smooth, ventral margin with small setae (Fig 14). Epimeral plate 2 with posteroventral corner acutely produced, posterior margin smooth, ventral margin with 4 stout setae (Fig 14). Epimeral plate 3 with posterior margin concave and smooth, posteroventral corner acute, slightly produced, ventral margin with 5 small setae (Fig 14). Uropod 1 with peduncle longer than rami, spur present, basofacial seta thin, dorsal margin with 5 setae; rami subequal in length, with 3 distal long setae on each one (Fig 14). Uropod 2 with peduncle subequal in length to rami, inner ramus slightly shorter than inner ramus, both ones with long setae (Fig 14). Uropod 3 peduncle subquadrate, shorter than rami; rami subequal in length; outer ramus with 3 sets of setae; inner ramus with 2 sets of setae (Fig 14). Telson deeply cleft, about 70%, telsonic lobes apically truncate with 5 robust setae longer than telson and 2 small lateral setae (Fig 14).
Female (Sexual dimorphic characters). Gnathopod 1 with anteroventral corner of coxa 1 rounded and produced, ventral margin with setae; basis strong, anterior margin with 3 long setae; ischium longer than merus; merus with posterior row of simple setae less dense than the ones on the males; carpus laterally expanded and less setose than on males, with posterior row of dense setae, anteroventral corner with row of medium setae; propodus about 0.2 times shorter than carpus, not facially setose, posterior and anterior margins beset with setae (Fig 12).
Gnathopod 2, coxa 2 with 4 setae on ventral margin; basis robust, posterior margin without setae; ischium shorter than merus; carpus reduced, boomerang-shaped with small setae; propodus greatly enlarged, anterior margin with slender setae, palm with a delicate rounded process near hinge of dactylus, proceeded by a sinuous excavation, palm defined by an acute and small spine; dactylus less robust than males one, ventral margin without processes (Fig 12).
Remarks. Quadrimaera miramirandella sp. nov. is closely related to Q. miranda and Q. mirandella by presenting a propodus palm with a medial U-shaped excavation, and a molar-shaped process, dactylar inner margin acutely produced and telson lobes apically truncated (Ruffo et al. 2000; Appadoo et al. 2002). Nevertheless, Q. miramirandella sp. nov. differs from Q. miranda by presenting: (1) gnathopod 1 carpus with plumose setae, instead of simple and slender setae; (2) gnathopod 2 with medial truncated excavation in propodus palm, while in Q. miranda it is rounded (Ruffo et al. 2000); (3) uropod 3 with rami subequal in length, while in Q. miranda it is unequal (Ruffo et al. 2000); (4) telson with a 70% cleft instead of 90% cleft (Ruffo et al., 2000). Quadrimaera miramirandella sp. nov. also differs from Q. mirandella by presenting (1) antenna 2 with cone gland not reaching the end of article 3 (while in Q. mirandella it reaches (Appadoo et al. 2002); (2) gnathopod 1 with coxa 1 with anteroventral corner produced and in Q. mirandella it is not produced (Appadoo et al. 2002); (3) gnathopod 1 with plumose setae on carpus (while in Q. mirandella the setae are simple); (4) telson with a 70% cleft while in Q. mirandella it is 60% (Appadoo et al. 2002), telsonic lobes with apical setae longer than telson while in Q. mirandella the setae are smaller than the telson (Appadoo et al. 2002).
The use of gnathopod 2 by some specimens of Quadrimaera miramirandella sp. nov. was observed in some organisms kept an aquarium. Males and females rely on the enlarged gnathopods to dispute territory, doing movements like punches towards undesirable elements. Moreover, the same specimens use the gnathopod 2 to dig and burrow in the sediment (Figs 20–21).
Quadrimaera miramirandella sp. nov. typically occurs in arenitic reef formations along the coast of the Ceará State.
description: Published as part of Alves, Jessika, Neves, Elizabeth & Johnsson, Rodrigo, 2018, A review of Quadrimaera Krapp-Schickel & Ruffo, 2000 (Amphipoda: Senticaudata) from Brazil, pp. 567-593 in Zootaxa 4532 (4) on pages 575-583, DOI: 10.11646/zootaxa.4532.4.8, http://zenodo.org/record/2615683