Collodes anartius, Colavite, Jessica, Windsor, Amanda & Santana, William, 2019

Colavite, Jessica, Windsor, Amanda & Santana, William, 2019, Three new species and a new genus of majoid crabs from the eastern Pacific (Decapoda, Brachyura), ZooKeys 825, pp. 1-24 : 4-8

Collodes anartius sp. n. Figures 2A, C, E, F; 3A, C; 4A, C, E, 7A, B

Holotype.

Peru, off Paita, Piura, Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 16, stn 625-A, 04°57' / 05°01'S; 81°23'W, 02.vi.1966, Smithsonian Oceanographic Sorting Center coll., 118-133 m, male, cl 27 mm, cw 23.5 mm (USNM 1462817).

Paratypes.

Peru, off Paita, Piura Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 16, stn 625-A, 04°57' / 05°01'S; 81°23'W, 02.vi.1966, Smithsonian Oceanographic Sorting Center coll., 118-133 m, 49 males, 7 females (USNM 1462747). Idem, 1 male (MZUSP 38889) 1 female (MZUSP 38890). Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 16, stn 626-B, 05°07' / 04°59'S; 81°27'W, 03.vi.1966, Smithsonian Oceanographic Sorting Center coll., 365-457 m, male, cl 28.47 mm, cw 24.0 mm, 1 female, cl 24.0 mm, cw 19.2 mm, illustrated (USNM 1462821). Idem, 16 males, 2 juvenile females, 2 females, 32 ovigerous females (USNM 1462818). Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 6, stn 627-A, 05°01'/ 04°59'S; 81°25'W / 81°25'W, 03.vi.1966, Smithsonian Oceanographic Sorting Center coll., 200-311 m, 4 males, 1 female (USNM 1462676).

Comparative material.

Collodes tenuirostris . Mexico, Sonora, Puerto Lobos, R/V Albatross, stn 3018, 30°16'00"N; 133°05'00"W, 24.iii.1889, USFC coll., MJ Rathbun det., 66 m, male holotype, 1 male paratype (USNM 17333). Costa Rica, off Playa Flamingo, R/V Urraca, stn CR– 23, 15.vii.2005, R Collin coll., 1 male, DNA only (ULLZ 8235). Gulf of Nicoya, vii.1979, 9°48.27'N; 85°08.43'W, 25 m, 2 ovigerous females (USNM 1462759). Panama, Gulf of Panama, R/V Shimada, stn 63, 08° 11'N; 79°36'W, 13.iv.1967, A Windsor det., 4 ovigerous female (USNM 1479280). Ecuador, Manabi, off Cape San Lorenzo, Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 18B, stn 775, 01°05'S; 80°98'W, 12.ix.1966, Smithsonian Oceanographic Sorting Center coll., 185 m, 1 juvenile male (USNM 1155058). Peru, west of Paita, Piura, Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 16, stn 624-E, 04°51' / 04°57'S; 81°20' / 81°23'W, 02.vi.1966, Smithsonian Oceanographic Sorting Center coll., 79-91 m, 4 males, 5 ovigerous female, 1 juvenile female (USNM 1462819). West of Paita, Piura, Southeast Pacific Biological Oceanographic Project (SEPBOP), R/V Anton Bruun, cruise 16, stn 625-A, 04°57' / 05°01'S; 81°23'W, 02.vi.1966, 118-133 m, 1 ovigerous female, DNA only (USNM 1479343).

Collodes gibbosus . Costa Rica, off Playa Flamingo, R/V Urraca, stn CR– 18, 15.vii.2005, R Collin coll., 15.5 m, 1 male, DNA only (ULLZ 8229). Ecuador, Salango Bay, Salango Island, R/V Velero III, Allan Hancock Pacific Expedition, stn 396-35, 18.i.1935, J Garth det., 22 m., neotype, female (USNM 100921).

Collodes granosus . Mexico, Baja California, San Lucas Bay, Cabo San Lucas, R/V Albatross, stn 5681, 23.iii.1911, MJ Rathbun det., 24 m, 1 ovigerous female (USNM 55766). Panama, Panama Bay, R/V Urraca, 24.ii.2007, DL Felder coll., 20-30 m, 1 male, DNA only (ULLZ 9760).

Collodes robsonae . Costa Rica, Gulf of Nicoya, 16.ii.1980, Dean & Howe coll., 70 m, 1 ovigerous female (USNM 1462812).

Collodes tumidus . Mexico, Baja California, Magdalena Bay, R/V Albatross, stn 2831, 24°32'00"N; 111°59'00"W, 02.v.1888, MJ Rathbun det., 22 m, holotype, male (USNM 21571).

Type-locality.

Peru, west of Paita, Piura, 04°57'S to 05°07'S; 81°23'W to 81°27'W, 118-133 m.

Diagnosis.

Carapace pyriform, granulose, particularly on cardiac, branchial and intestinal regions. Second antennal article ventrolateral surface with strong, unarmed longitudinal keel. Third maxillipeds granulated; ischium and carpus with dense granulation, propodus smooth. First pleonal segment with a short spine or distinctly strong tubercle with several small tubercles around. P2-P5 dactylus smooth ventrally; dactylus of P5 longer than propodus; carpus of P5 more than half of merus.

Description.

Carapace pyriform, longer than wide; dorsal surface covered by tubercles of different sizes (more prominent in females), particularly on cardiac, branchial and intestinal regions; gastric and branchial regions covered with hooked setae. Gastric, branchial, cardiac, intestinal regions with small tubercles. Gastric, hepatic, branchial, cardiac, intestinal regions clearly delimited laterally by grooves. Metagastric region with mesial prominent tubercle; gastric region with few small tubercles; mesocardiac region with four tubercles in line longitudinally, distal tubercles more prominent. Groove between cardiac and intestinal region smooth or with a few small tubercles in males and females. Hepatic, branchial, intestinal regions densely covered with sub-equal tubercles. Metabranchial region slightly depressed. Thoracic pleurites V–VIII gymnopleura not fused to one another, usually densely covered with small hooked setae.

Rostrum simple, short, slightly curved upwards. Supraorbital spine absent; orbital margin unarmed dorsally. Postorbital spine longer than the ocular peduncle, directed laterally and upwards around eyes. Antennular fossae longitudinally ovate; anteroventral margin unarmed. Interantennular septum longer than epistomial spine, compressed laterally, forming ventrally-directed keel. Antenna (flagellum included) distinctly exceeding rostral length. First and second antennal articles fused to epistome. Second article protruding anterolaterally; ventrolateral surface with strong longitudinal keel, unarmed; ventrolateral margin dentate, teeth acute. Third antennal article massive; fourth longest, cylindrical; fifth article smaller.

Epistome markedly wider than long. Epistomial spine separated by small gap from interantennular septum. Mouthfield sub-rectangular. Pterygostomial region subtriangular, smooth near mouth frame, densely tuberculated laterally, tubercles sub-equal. Sub-hepatic region strongly swollen, delimited from pterygostome by distinct slope, densely covered with sub-equal tubercles, several long setae.

Third maxillipeds almost completely covering buccal frame, ischia leaving distinct gap. Exopod long, nearly reaching distal margin of merus; granulated; lateral margin with strong lobe in proximal third. Ischium distinctly longer than broad, dorsal face with longitudinal, smooth, deep groove; with granules; mesial margin slightly convex; crista dentata with small, rounded, irregularly sized teeth. Merus slightly longer than half of ischium, granulated. Anterior margin deeply incised, anterolateral and anteromedial margins expanded, mesial margin with a row of setae. Palp cylindrical, slightly overreaching ischiomeral suture. Carpus granulated; propodus and dactylus smooth, fringed with row of long setae.

Thoracic sternites II–IV broadly triangular in males, with sparse hooked setae, small tubercles medially. Anterior half of sternites I–IV strongly sloping down laterally, forming prominent triangle medially; fourth sternite densely tuberculated, with smaller projection ventrally directed in males. Male sternites IV–VII covered with distinct, large tubercles, outside sterno-pleonal cavity; smooth in females.

Male and female chelipeds sub-cylindrical, homochelous, robust in males, slender in females. Dactylus (movable) and fixed finger approximately same length as palm in males and females, covered with sparse setae. Males with finger cutting edges with small teeth, sub-equal in distal half, leaving distinct proximal depressed gap in sub-proximal edge of dactylus. Distal two-thirds of finger cutting edges with sub-equal teeth in females. Male propodus conspicuously inflated, with sparse setae, small tubercles in dorsal margin, fewer tubercles in ventral margin. Propodus slender, smooth in females. Carpus setose, with several tubercles dorsally, unarmed in females. Merus with two rows of small tubercles in dorsal and mesoventral faces, row of strong tubercles in lateral face, with long setae. Ischium sparsely tuberculate, setose. P2-5 similar in shape, slender, cylindrical; P2 longest, P3-P5 progressively decreasing in length. Dactylus of P3-P5 longer than propodus, without tubercles, carpus more than half of merus. Dactylus, propodus, carpus, merus densely setose, covered with long setae interspersed with hooked setae.

Male pleonal somites I–V free, sixth fused to telson. Pleotelson sub-triangular, rounded distally. Female pleonal somites I–IV free, somites V, VI, telson fused; pleotelson markedly arched, transversally oval. Male and female first pleonal somite with short spine or strong tubercle with several tubercles surrounding. Male somite I densely tubercular; somite VI-telson with scattered tubercles in the anterior margin. Female somites II–IV tubercular laterally; somites V–VI, telson evenly, densely tubercular in mesolateral region.

Distribution.

Northwest of Peru, from 04°57'S to 05°01'S; 81°23'W, 118 to 457 m.

Etymology.

The specific epithet is derived from the Greek adjective anartius for “uneven”, alluding to the rough similarity between the new species and C. tenuirostris and contours of the carapace.

Remarks.

Although the phylogenetic analyses of seven of the 15 described species of Collodes pointed to C. robustus , a western Atlantic species, as the sister species of C. anartius they are very distinct morphologically, with characters that clearly differentiate both species. For instance, (i) dorsal surface covered by tubercles of different sizes (more prominent on females) in C. anartius (vs. carapace evenly covered by small, similar in size tubercles in males and females of C. robustus ); (ii) sternites V–VII with few, distinct, large tubercles in C. anartius (vs. sternites IV–VII with numerous, small, evenly distributed tubercles in C. robustus ).

Collodes anartius superficially resembles C. tenuirostris Rathbun, 1893, in the general morphology with respect to size and distribution of carapace tubercles, the postor bital spines are also very similar in both species (Fig. 2A, B). Because they inhabit the same substrates, mud bottoms, and have the habit of completely camouflaging in the sediment, these species are difficult to separate. The bathymetric range was nevertheless different for both species in the Peruvian coast, wherein C. anartius can be found in deeper regions (118-457 m) than C. tenuirostris (25-133 m) (vide material examined).

Morphological characters that can distinguish C. anartius from C. tenuirostris , are: (i) third maxillipeds granulated; ischium and carpus with dense granulation, propodus smooth (in C. anartius ) (vs. third maxilliped ischium and carpus sparsely granulate; propods granulate in C. tenuirostris ) (Fig. 2A, B); (ii) first pleonal segment with a short spine or strong tubercle with several small tubercles around in C. anartius (vs. pleonal spine usually longer, with very few small tubercles around it in C. tenuirostris ) (Fig. 2C, D); (iii) in males of C. anartius the fourth sternite has a small projection ventrally directed (vs. inflated projection in the fourth sternite in C. tenuirostris ) (Figs 3A, B; 4 A–D); (iv) all segments of female pleon of C. anartius are narrower, with fewer tubercles than in C. tenuirostris (Fig. 4E, F); (v) cutting edges of male cheliped fingers with small, sub-equal teeth in distal half and a distinct depressed gap distally in C. anartius (vs. well defined teeth in the cutting edges of fingers up to the distal gap in C. tenuirostris ) (Fig. 2A, B); (vi) P2-P5 dactylus smooth ventrally in C. anartius (vs. P2-P5 dactylus with very small spines ventrally in C. tenuirostris , sometimes the spines are worn) (Fig. 2C, D); (vii) dactylus of P5 longer than propodus (vs. P5 dactylus and propodus of same size or dactylus smaller than propodus in C. tenuirostris ) (Figs 2C, D; 4G, H); (xi) carpus of P5 more than half of merus in C. anartius (vs. carpus of half or less of the size of merus in C. tenuirostris ) (Figs 2C, D; 4G, H).