Caleidoscopsis karamani, Do Nascimento & Serejo, 2023

Do Nascimento, Priscila S. & Serejo, Cristiana S., 2023, New findings of the family Pardaliscidae from the deep-sea southwestern Atlantic the genus Caleidoscopsis Karaman, 1974, Zootaxa 5256 (2), pp. 139-157 : 150-156

Caleidoscopsis karamani sp. nov.

( Figures 5–7 )

Material examined. Holotype: male, length 2.4 mm, Sta. HAB8 A08 R1 , MNRJ 24667 (holotype specimen preserved in ethanol; dissected slides lost in the 2018 Museu Nacional fire) . Paratypes: 1 male, 2.9 mm, Sta. HAB8 B09 R3 (0-2) , MNRJ 24668 (dissected on slide) ; 1 male, 2.7 mm, Sta. AMB6 CANWN7 R3 , MNRJ 30429 (dissected on slide) ; 1 male, 3.7 mm, Sta. AMB12 CAND6 R3 , MNRJ 30430 (dissected on slide) ; 1 male, Sta HAB3 B08 R3 (0-2) , MNRJ 24699 .

Etymology. In honor to Dr. Gordan S. Karaman (Montenegrin Academy of sciences and arts, Podgorica, Montenegro), a reference in the study of Amphipoda taxonomy, including the family Pardaliscidae , which is the object of the present work.

Diagnosis. Rostrum well-developed, reaching half-length of article 1 of peduncle of antenna 1. Antennae 1–2, flagellum with long articles, each one at least 2x longer than wide. Antenna 1 simple, not geniculate; first article of primary and accessory flagellum fused, callynophore present. Maxilliped, palp article 4 smooth, without tooth on the inner margin. Coxa 5 slightly subtriangular. Pereopod 7, basis thin, 2x longer than wide; propodus 13x longer than wide. Epimeral plate 3 posteroventral angle with a tooth, not exceeding end of urosomite 1. Urosomite 1 covering part of urosomite 2, with 1 long dorsal tooth; urosomite 2 with 1 very long dorsal tooth almost reaching the end of urosomite 3. Uropod 3, outer ramus, article 2, 35% length of the ramus size. Telson cleft about 60% of its length.

Description. Male, holotype, 2.4 mm, MNRJ 24667. Head wider than long; cephalic lobe present; rostrum present, well-developed, reaching half-length of article 1 of peduncle of antenna 1; eyes absent.

Antenna 1 simple, not geniculate, peduncle reaching less than half of the peduncle of antenna 2; article 1 the longest, 4x the length of the article 2, with short plumose and simple setae, article 2 with a few simple setae distally, article 3 slightly shorter than article 2, naked; primary flagellum with 8 long articles, each one at least 2x longer than wide, article 1 fused, 0.7x the size of the peduncle, distal simple setae on each article, aesthetascs present, callynophore present; accessory flagellum with 4 articles, article 1 fused, flat, with 2 groups of simple setae, distal projection over article 2–3, article 2 with distal simple setae.

Antenna 2, longer than antenna 1, articles 3–4 of peduncle subequal in length and width, article 4 with simple setae, article 5 1.5x longer than article 4, narrower, with 4 anterior groups of simple setae; broken flagellum, 10 long articles present, each one at least 2x longer than wide, with distal simple setae.

Mouthparts forming a quadratiform bundle. Upper lip asymmetrically incised.

Lower lip, inner lobes coalesced.

Right mandible, incisor strongly dentate, with 4 sharp teeth, 2 bigger than the other 2, lacinia mobilis slender, sharp, 1 raker present, row of small setae. Left mandible, incisor divided into 2 short teeth and a microdentate surface with blunt teeth, lacinia mobilis wide, more than half the incisor width, microdentate, 1 raker present, row of small setae; molar absent in both mandibles; palp 3-articulated on both sides, articles 1–2 naked, article 2 3x longer than 1, article 3 subequal in length to article 2, with 3 apical simple setae.

Maxilla 1, inner plate reduced, with 1 simple seta apically; outer plate with 6 apical robust setae; palp 2- articulated, article 2 expanded distally, with 3 subapical simple setae and 7 apical robust setae.

Maxilla 2, short plates, about 2x longer than wide, plates subequal in length; inner plate with 3 simple setae on the inner margin, 2 simple setae and 1 plumose seta apically; outer plate with 2 simple setae and 1 plumose seta apically.

Maxilliped, inner plate reduced, narrow, with 2 apical simple setae; outer plate, not exceeding article 1 of the palp, with 4 simple setae on the inner margin and 3 robust setae apically. Palp 4-articulated, article 1 naked, article 2 with a few simple setae on the inner margin, article 3 with a few simple setae in the distal half, article 4 shorter than 3, with a tooth on the inner margin and 1 small simple seta.

Coxae 1–4 longer than wide, exceeding half-length of the basis; coxa 5 well-developed, as long as wide, reaching half-length of the basis, not bilobed, slightly triangular; coxae 6–7 very short, not bilobed, wider than long.

Gnathopod 1, basis with 1 simple seta on posterodistal angle; merus with 3 simple setae; carpus 1.5x longer than wide, shorter than propodus, with 3 plumose setae and a few simple setae; propodus 2x longer than wide, with 5 plumose setae and a few simple setae; palm absent (simple), dactyl smooth with 1 short simple seta.

Gnathopod 2 similar to 1 in shape and size, more setose; basis and ischium with 1 simple seta on posterodistal angle on each one; carpus 2x longer than wide, with a few simple and plumose setae with small setules; propodus with plumose setae with small setules.

Pereopod 3, basis and ischium narrow, with 1 simple seta distally; merus about 2.5x longer than wide with simple setae on ventral margin; carpus, about 2x longer than wide with simple setae on ventral margin; propodus subequal in length to carpus, narrower, with 3 distal simple setae; dactyl subequal to propodus, simple, not subdivided. Pereopod 4 similar to 3 in shape, size and setation.

Pereopod 5 about 1.5x longer than pereopod 4; basis without a posterior lobe, narrow, 2x longer than wide; basis and merus with simple setae on anterior margin; carpus and propodus with a few simple setae in the distal half; propodus 10x longer than wide; dactyl as long as propodus.

Pereopod 6 about 1.5x longer than pereopod 5, similar in setation; basis without a posterior lobe; propodus 10x longer than wide; dactyl as long as propodus.

Pereopod 7 subequal in length and setation to pereopod 6; basis thin, 2x longer than wide, with posterior lobe almost reaching the end of ischium; propodus 13x longer than wide; dactyl as long as propodus.

Epimeral plate 1, sinuous posterior margin. Epimeral plates 1–2 with 1 small simple seta on the ventral margin of each one, and posteroventral angle forming a small tooth. Epimeral plate 3, posteroventral angle with a tooth not exceeding the end of urosomite 1.

Pleopods well-developed, basal article of ramus not fused, about 10 articles, very setose.

Urosomite 1 covering part of urosomite 2, with 1 long dorsal tooth. Urosomite 2 with 1 very long dorsal tooth almost reaching the end of urosomite 3.

Uropod 1, peduncle subequal to rami in length, 1 robust seta on inner margin and 3 robust setae on outer margin; biramus, rami subequal in length, apically pointed, outer ramus with 2 dorsal robust setae, inner ramus dorsal margin naked, both rami with a subapical simple seta.

Uropod 2, peduncle subequal to rami in length, with only 1 robust seta on outer margin; biramous, rami subequal in length, apically pointed, outer ramus with 2 dorsal robust setae, inner ramus dorsal margin naked, both rami with a subapical simple seta.

Uropod 3, peduncle short, ramus 3.5x the length of the peduncle, peduncle with a set of 4 robust setae distally on the outer margin and 1 robust seta on inner margin; biramous, lanceolate; both rami naked; outer ramus 2- articulated, article 2 35% the length of the ramus.

Telson 1.5x longer than wide, cleft about 60% the length, with 2 dorsofacial small plumose setae on each lobe.

Type locality. Campos Basin (23°41′07.81′′S, 41°16′04.71′′W), Brazil, Southwestern Atlantic Ocean, 1.017 m .

Distribution. Caleidoscopsis karamani sp. nov. is known from Campos Basin and Espírito Santo Basin (19°– 23°S), Brazil, Southwestern Atlantic, from 986–1290 m depth ( Fig. 1 ).

Remarks. The present description is based on males only. Species observed presented the penial papilla and no oostegites. Further on, antenna 1 presented first article of flagellum (primary and accessory) fused and with callynophores, characters typical of some male pardaliscid genera. Caleidoscopsis karamani sp. nov. can be easily distinguished from all Caleidoscopsis species by: rostrum more developed, reaching half-length of article 1 of peduncle of antenna 1; antenna 2, peduncle, article 5 longer than 3 and 4; pereopod 7, propodus 13x longer than wide, subequal to dactylus; urosomite 1 covering part of urosomite 2, with 1 long dorsal tooth; urosomite 2 with 1 very long and thin dorsal tooth almost reaching the end of urosomite 3. Morphological comparison between the six known Caleidoscopsis species is shown in Table 2 .

Figures

FIGURE 1. World distribution of Caleidoscopsis species. Stations along the Brazilian coast (19o–27o S) were collected between 417–1974 m depths, from projects AMBES, HABITATS and PCR–Santos, all from slope campaigns.

FIGURE 5. Caleidoscopsis karamani sp. nov. Male, 2.4 mm, holotype, Sta. HAB8 A08 R1, Campos Basin, MNRJ 24667. Habitus, head (dorsal) and antennae. Male, 2.9 mm, paratype, Sta. HAB8 B09 R3, Campos Basin, MNRJ 24668. Mouthparts. Scale = 0.1 mm.

FIGURE 6. Caleidoscopsis karamani sp. nov. Male, 2.4 mm, holotype, Sta. HAB8 A08 R1, Campos Basin, MNRJ 24667. Gnathopods 1–2, pereopods 3–4, urosomites dorsal view (left) and lateral view (right). Male, 2.7 mm, paratype, Sta. AMB6 CANWN7 R3, Espírito Santo Basin, MNRJ 30429. Gnathopod 2, pereopods 3–4 (asterisk). Scale = 0.1 mm.

FIGURE 7. Caleidoscopsis karamani sp. nov. Male, 2.4 mm, holotype, Sta. HAB8 A08 R1, Campos Basin, MNRJ 24667. Pereopods 5–7, epimeral plates, uropods and telson. Scale = 0.1 mm.