Campylaspis bicurvata, Duda & Roccatagliata & Lucatelli & Souza- Filho, 2025

Campylaspis bicurvata sp. nov.

( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Material examined. Holotype: 1 subadult female (3.4 mm), T700 N 4#10, 21º14’34.508”S 40º12’39.398”W, 700 m depth, April 2019, MOUFPE 21056 View Materials GoogleMaps . Paratypes: 1 juvenile female (2.0 mm), T700 N 4#20, 21°6’15.966”S 40°11’54.089”W, 688 m depth, April 2019, MOUFPE 21039 View Materials GoogleMaps ; 1 subadult male (2.2 mm), T700 N 4#17, 21º8’20.076”S 40º12’20.329”W, 726 m depth, April 2019, MOUFPE 21040 View Materials GoogleMaps ; 1 subadult male ( SEM photographs) T700 N 4#19, 21º6’34.517”S 40º11’52.285”W, 702 m depth, April 2019, MOUFPE 21041 View Materials GoogleMaps ; 1 subadult male T700 N 4#04 (dissected and drawn), 21º19’43.262”S 40º12’25.232”W, 700 m depth, April 2019, MOUFPE 21042 View Materials GoogleMaps ; 1 juvenile male (1.8 mm), T700 S 5#10, 23º42’57.884”S 41º20’44.801”W, 686 m depth, April 2019, MOUFPE 21686 View Materials GoogleMaps ; 1 juvenile female (1.2 mm), T700 N 4#12, 21º11’42.702”S 40º12’30.265”W, 733 m depth, April 2019, MOUFPE 21687 View Materials GoogleMaps ; 1 juvenile male (2.2 mm), T700 N 4#02, 21º21’4.849”S 40º11’51.918”W, 705 m depth, April 2019, MOUFPE 21688 View Materials GoogleMaps .

Diagnosis. Carapace strongly sculptured; each side with upper and lower oblique ridges surrounding a deep depression. This depression is divided into a posterior large area (A2) and a small anterior area (A1) by a vertical ridge. Upper oblique ridge u-shape at its posterior half, surrounding an oval dorsal area (A3). Eyelobe much longer than wide, no lenses. Second pereopod, dactylus 1.5 × carpus length, with apical digitiform process.

Description of the subadult female (based on the Holotype MOUFPE 21056 and Paratype MOUFPE 21041).

Integument well calcified, showing a hexagonal pattern.

Carapace ( Fig. 1 View FIGURE 1 , Fig. 2A, B View FIGURE 2 , Fig. 4B, D View FIGURE 4 ) 1.6 × longer than wide, with a few scattered setae both dorsally and laterally. Sides with 2 oblique tuberculate ridges, leaving a deep depression in between, which is divided into a posterior large area (A2) and a small anterior area (A1) by a vertical ridge. Upper oblique ridge starts from base of pseudorostrum, directed backwards, and turns forward to form on the dorsal surface a nearly closed loop that encircle a third area (A3). Lower oblique ridge starts from antennal notch running backwards close to carapace inferior margin to finally meet the opposite lower oblique ridge at mid-dorsal line, right and left ridges delimiting a small triangular area dorsally, with two large tubercles just in front of this triangular area. Pseudorostrum upturned about 30°, 0.14 × carapace total length. Siphons approximately as long as the pseudorostrum. Eyelobe small, much longer than wide, no lenses. Frontal lobe with a transverse row of 5–7 tubercles, most lateral tubercles (prominences, after Jones, 1974) large and carrying 1–2 setae, central tubercles smaller without setae (other specimens examined with 2, 3, or 5 central tubercles). With 4 tubercles, arranged in two rows, behind the frontal lobe, anterior tubercles larger than posterior ones (two additional specimens examined with 6 tubercles arranged in three rows, anterior pair larger than the others). Anteroventral margin smooth or faintly serrate. Antennal notch small.

Pereon ( Fig. 4A View FIGURE 4 ) segments 3–5 with 2 dorsal tubercles. All segments with lateral margins serrate.

Pleon ( Fig. 2A View FIGURE 2 , Fig. 4C View FIGURE 4 ) 0.6 × cephalothorax length. Pleonites 1–4 with 2 tubercles dorsally, and with 1 serrate projection and 1 row of teeth (below the projection), on each side. Pleonite 5 with 1 transverse ridge at midway of segment, and 1 row of teeth laterally.

Description of the appendages (based on a subadult male Paratype MOUFPE 21042).

Antenna 1 ( Fig. 2D View FIGURE 2 ) Peduncle of 3 articles, first article, 1.3 x second article, with 3 simple setae, second article subequal to third, with 1 simple seta; third article with 2 simple and 2 broom setae. Main flagellum of 3 articles, decreasing in length distally, first article glabrous, second article with 1 aesthetasc and 1 short simple seta; third article with 1 aesthetasc and 2 simple setae (1 long, 1 short). Accessory flagellum of 1 article, with 1 short simple seta and 2 broom setae.

Antenna 2 on development, with 2 articles.

Mouthparts typical of the genus. Mandible with the molar process styliform. Second maxilla reduced to a simple plate without movable endites.

Maxilliped 1 ( Fig. 2E View FIGURE 2 ): basis as long as remaining articles together, with 2 coupling hooks, endite with 1 simple and 2 setose setae. Ischium visible only on one side. Merocarpus 0.8 × basis length, inner margin with 6 simple setae, outer margin with 2 setae (1 setose, 1 simple). Dactylus 0.2 × merocarpus length with 1 simple terminal seta.

Maxilliped 2 ( Fig. 2F View FIGURE 2 ): basis as long as remaining articles together, with 1 large setose seta on inner distal margin and 1 simple seta on outer margin. Merus 0.4 × basis length, with 1 large setose seta distally. Carpus 0.5 × merus length, with 2 setose setae and 2 teeth distally. Propodus process on outer distal angle extending beyond dactylus teeth. Dactylus with 3 teeth, central one shortest.

Maxilliped 3 ( Fig. 3A View FIGURE 3 ) basis 0.9 × as long as remaining articles together, with 2 setose and 1 simple setae distally. Ischium glabrous, with teeth on inner margin. Merus 0.4 × basis length, inner margin with 3 simple setae and serrations. Carpus 0.3 × merus length, both margins with 1 setose seta and serrations. Propodus 2 × as long carpus, with 2 setose setae on inner margin, 1 setose seta on outer distal angle, and teeth on both margins. Dactylus 0.6 × propodus length, with 3 simple setae (1 broken) distally. Exopod, basis glabrous, flagellum of 4 articles, with large setae (not drawn).

Pereopod 1 ( Fig. 3B View FIGURE 3 ): basis 0.7 × as long as remaining articles together, with 2 setose setae distally. Ischium with 1 setose seta. Merus with 7 barely setose or simple setae, outer margin with a few teeth. Carpus 0.7 × as long as merus, with 8 barely setose or simple setae, outer margin with a few teeth. Propodus 1.1 × as long as carpus, with 9 barely setose or simple setae. Dactylus 0.7 × propodus length, with 9 simple setae. Exopod, basis with a simple seta and a few teeth, flagellum of 5 articles, with large setae (not drawn).

Pereopod 2 ( Fig. 3C View FIGURE 3 ) basis 0.5 × as long as remaining articles together, with 2 barely setose setae. Ischium glabrous. Merus with 3 barely setose or simple setae. Carpus 1.5 × as long as merus, laterally with 2 simple and 1 setose setae, distally with 1 barely setose, 1 simple and 1 short robust setae. Propodus glabrous. Dactylus (including digitiform process) 1.5 × as long as carpus, with simple and barely setose setae laterally, and 4 setae (3 large setulate; 1 minute, simple) distally, largest distal seta almost as long as article; distal end with a digitiform process extending beyond setae insertion (see detail Fig. 3C View FIGURE 3 ). Exopod, basis with a single seta, flagellum of 5 articles with large setae (not drawn).

Pereopod 3 ( Fig. 3D View FIGURE 3 ) basis 1.0 × as long as remaining articles together, with barely setose and simple setae. Ischium with 1 simple seta on outer distal angle. Merus with 2 simple setae (1 broken) on outer distal angle. Carpus 1.9 × as long as merus with 5 simple setae (3 laterally, 2 on outer distal angle). Propodus 0.4 × as long as carpus, with 2 simple setae distally. Dactylus 0.5 × as long as propodus, with 3 setae (distal one 2 × as long as article). Exopod, flagellum of 2 articles.

Pereopod 4 ( Fig. 3E View FIGURE 3 ) basis 0.8 × as long as remaining articles together, with barely setose and simple setae. Ischium with 1 small simple seta. Merus with 2 setae (1 simple, 1 serrulate) on outer distal angle. Carpus 2 × as long as merus with 4 simple setae (2 at midway of article, 2 unequal on distal outer angle). Propodus 0.4 × as long as carpus, with 1 simple seta on outer distal angle. Dactylus 0.7 × as long as propodus, with 3 setae (distal one 2 × as long as article). Exopod, flagellum of 1 article.

Pereopod 5 ( Fig. 3F View FIGURE 3 ) basis 0.3 × as long as remaining articles together, with 2 simple setae and 1 tooth. Ischium with 1 small simple seta. Merus with 1 simple seta. Carpus 1.8 × as long as merus, glabrous. Propodus 0.4 × as long as the carpus, with 1 simple seta on distal angle. Dactylus 0.6 × as long as the propodus, with 3 simple setae (distal one 2.6 × as long as article). Without exopod.

Uropod ( Fig. 2C View FIGURE 2 ) peduncle 1.8 × as long as last pleonite, with serrations on both margins. Rami subequal. Endopod 0.6 × peduncle length, with 3 robust setae on inner edge (2 lateral, 1 subterminal), and 2 robust setae distally (1 large, 1 small). Exopod, distal article with 1 small seta on each side, and 2 unequal setae (largest slightly longer than article) distally.

Etymology. The epithet refers to the u-shaped posterior portion of each upper oblique ridge, which defines the dorsal areas A3 on the carapace.

Type locality. Campos Basin , off Espírito Santo State, 21º14’34.508”S 40º12’39.398”W, 700 m depth GoogleMaps .

Distribution. Known only from Campos Basin, Rio de Janeiro and Espírito Santo States, Brazil, 686–733 m depth ( Fig. 8 View FIGURE 8 ).

Remarks. Campylaspis bicurvata sp. nov. is most similar to C. chisamerai Petrescu, 2018 ( Australia). Both species share the following features: pseudorostrum long and upturned; siphons relatively long; sides of carapace with two oblique ridges; areas A1, A2 (schematized in Fig. 1 View FIGURE 1 ) well defined; frontal lobe with a transverse row of tubercles; dactylus of pereopod 2 with a digital process. Campylaspis bicurvata sp. nov. can be easily separated from C. chisamerai by having a well-defined A3 (poorly defined in C. chisamerai ) and a long eyelobe (short in C. chisamerai ). Differences between Campylaspis bicurvata sp. nov. and C. chisamerai , and other similar species are listed in Table 1 View TABLE 1 . The following morphological features are common to all these species: carapace with welldeveloped upper and lower ridges running obliquely backwards and defining the areas A1 and A2 when the anterior vertical ridge is present; posterior vertical ridge absent or poorly developed (except in C. undata ); dorsal surface of carapace uneven due to the presence of many tubercles (except in C. exarata , which only has on a blunt prominence on each side of frontal lobe).