Oncopagurus, Lemaitre, 1996

Lemaitre, Rafael, 2014, A worldwide taxonomic and distributional synthesis of the genus Oncopagurus Lemaitre, 1996 (Crustacea: Decapoda: Anomura: Parapaguridae), with descriptions of nine new species, Raffles Bulletin of Zoology 62, pp. 210-301 : 213-214

Key to the Indo-West Pacific species of Oncopagurus *

[* Oncopagurus sp. A , reported by Zhadan (1997), excluded from key]

1. Cornea subconical or reduced (width no greater than distal width of ocular peduncle).......................................................2

– Cornea not subconical or reduced (width greater than distal width of ocular peduncle).......................................................5

2. Cornea distally rounded; uropods and telson distinctly asymmetrical; right chela operculate......................................3

– Cornea distally acute, usually sharply so ( Fig. 10L ); uropods and telson symmetrical; right chela not operculate ................. ................................................................................. O. conicus

3. Antennal acicle short, not exceeding distal margin of corneas or at most exceeding distal margin by 0.2 length of acicle (in O. elongatus , new species); right cheliped with chela relatively broad (length/width no more than 1.3)...................................4

– Antennal acicle long, exceeding distal margin of cornea by nearly half length of acicle ( Fig. 31A ); right cheliped with chela relatively slender (length/width distinctly more than 1.3)....... ............................................................. O. petilus , new species

4. Right cheliped sexually dimorphic (in females, palm with mesial face expanded distomesially, and ventromesial margin well delimited by row of spines; in males, palm with mesial face not expanded distally, and ventromesial margin at most weakly delimited by small tubercles; Fig. 22A–D ); dactyl of fourth pereopod long and slender, 1.8–2.5 times as long as dorsal margin of propodus, sexually dimorphic, longer and slenderer in females than in males ( Fig. 23E, F ); gills biserial to weakly quadriserial. ................... O. elongatus , new species

– Right cheliped not sexually dimorphic (in both sexes, palm with mesial face not expanded distomesially, and ventromesial margin of palm not well delimited; Fig. 27C, D ); dactyl of fourth pereopod short, no more than 1.5 times as long as dorsal margin of propodus, not sexually dimorphic; gills biserial..... ................................................................................. O. minutus

5. Antennal acicle not exceeding distal margin of cornea (at most reaching to about mid-portion of cornea)...............................6

– Antennal acicle reaching to or slightly exceeding distal margin of cornea................................................................................12

6. Ventral surface of right chela with tuberculate ridges or cluster of tubercles on ventral surface of palm, and distinct tuberculate longitudinal ridges on fixed finger and dactyl.......................7

– Ventral surface of right chela unarmed, smooth or at most with scattered small tubercles, lacking ridges or tubercles on palm or distinct ridges on fixed finger and dactyl..........................8

7. Ventral surface of palm of right chela with distinct median cluster of tubercles ( Fig. 24D, E ); ocular acicles each terminating in submarginal spine ( Fig. 24B )................................. O. glebosus

– Ventral surface of palm of right chela without median cluster of tubercles, instead with median longitudinal tuberculate or spinose ridges continued on fixed finger and towards mesiodistal angle, forming Y-shape ( Fig. 40B ); ocular acicles each terminating in simple spine (not submarginal)................ ......................................................... O. rossanae , new species

8. Epistomial spine bifid ( Fig. 2C ); telson sexually dimorphic (terminal margins of lobes armed with slender, corneous spines stronger and more numerous in females than in males, and extending to midportion of left lateral margin; in females, left lobe armed with 16–20 long and short spines, of which 2 or 3 are strong and curved or bent at nearly right angle; Fig. 5D, E ). ........................................................ O. bifidus , new species

– Epistomial spine simple; telson not sexually dimorphic.......9

9. Palm of right cheliped with distomesial angle mesially not expanded or thumb-like........................................................10

– Palm of right cheliped with distomesial angle mesially expanded, thumb-like ( Fig. 36A, B ). .................. O. pollicis , new species

10. Carpi and propodi of ambulatory legs armed on dorsal margin with row of small spines ( Fig. 45A–C ).................................... ........................................................ O. spiniartus , new species

– Carpi and propodi of ambulatory legs unarmed on dorsal margin except for small dorsodistal spine on carpi..........................11

11. Merus of right cheliped with thick, yellow bristle-like setae on dorsal margin ( Fig. 8A, E ); male lacking first gonopods, and with poorly developed, asymmetrical second gonopods ( Fig. 6F, G ).................................................... O. brevis , new species

– Merus of right cheliped without thick bristle-like setae on dorsal margin; male with first gonopods, and symmetrical second gonopods.............................................................. O. curvispina

12. Ocular acicles multifid or occasionally bifid ( Fig. 30A ). ........ .............................................................................. O. orientalis

– Ocular acicles simple............................................................13

13. Propodal rasp of fourth pereopod with 1 row of ovate scales................................................................................................14

– Propodal rasp of fourth pereopod with 2 rows of ovate scales ( Fig. 49E )............................................................. O. stockmani

14. Palm of right cheliped with ventromesial face normally rounded, not elevated as broad, rounded ridge, and ventral face smooth or with scattered tubercles....................................................15

– Palm of right cheliped with ventromesial face elevated as broad, rounded tuberculate ridge projecting distally near base of dactyl, and ventral face with raised cluster of small blunt spines ( Fig. 18C–E )........................... O. elevatus , new species

15. Palm of right cheliped with ventromesial margin distinctly delimited by row of spines, more so in females than in males......................................................................................16

– Palm of right cheliped with ventromesial margin rounded, not distinctly delimited in either sex...........................................17

16. Antennal flagellum with numerous long setae 1–3 flagellar articles in length; right cheliped not sexually dimorphic (in both sexes, palm with mesial face expanded distomesially ( Fig. 50B, C ), and ventromesial margin well delimited by row of spines), and row of strong spines on dorsodistal margin of carpus; males lacking first gonopods and with asymmetrical second gonopods .................................................... O. tuamotu

– Antennal flagellum with scattered short setae less than 1 flagellar article in length; right cheliped sexually dimorphic (in females, palm with mesial face expanded distomesially, and ventromesial margin well delimited by row of spines; in males, palm with mesial face not expanded distally, and ventromesial margin weakly delimited), and weakly armed dorsodistal margin of carpus; males with first gonopods, and symmetrical second gonopods................................................................... O. indicus

17. Cornea not dilated; males lacking first gonopods, second gonopods reduced or vestigial; maximum size relatively small (sl <3 mm)............................................................................18

– Cornea dilated ( Fig. 28A ); males with first and second gonopods ( Fig. 28K, L ); maximum size relatively large (shield length up to 6 mm or more)............................................... O monstrosus

18. Antennal peduncle at most reaching to distal margin of cornea; dactyl of fourth pereopods sexually dimorphic, distinctly slenderer and more strongly curved (hook-like) in females than in males ( Fig. 10E, F ); second gonopods reduced (1- or 2-segmented, occasionally absent on right side; Fig. 10H, I ). .................................................................................. O. cidaris

– Antennal peduncle exceeding distal margin of cornea by 0.3 length of fifth segment; dactyl of fourth pereopods not sexually dimorphic ( Fig. 29G ); second gonopods vestigial (bud-like or very short segment; Fig. 29I, J )................................. O. oimos

Figures

Fig. 10. A–J, Oncopagurus cidaris Lemaitre, 1996, Queensland, Australia (QM W16596):A–E, G, H, J, paratype, male 2.9 mm; F, paratype, female 2.6 mm; I, paratype, male 2.7 mm. A, shield and cephalic appendages, dorsal; B, right cheliped, dorsal; C, chela of same, mesial; D, dactyl of left first ambulatory leg, mesial; E, F, propodus and dactyl of left fourth pereopod in male (E) and female (F), lateral; G, I, male left second gonopod, lateral; H, male right second gonopod; J, telson, dorsal. K–S, Oncopagurus conicus Lemaitre, 2006, holotype, male 2.0 mm, New Caledonia, (MNHN Pg 7612): K, shield and cephalic appendages, dorsal; L, right ocular peduncle, lateral; M, right cheliped, dorsal; N, chela of same, lateral; O, dactyl of left first ambulatory leg, mesial; P, propodus and dactyl of left fourth pereopod, lateral; Q, left first gonopod, mesial; R, left second gonopod, anterior; S, uropods and telson, dorsal. Scale bars = 2 mm (A–F); 0.5 mm (G–J); 0.5 mm (K, L, S); 1 mm (M, N, O); 0.2 mm (P–R). [Adapted from Lemaitre (1996, 2006)].

Fig. 31. Oncopagurus petilus, new species: holotype, male 4.6 mm, eastern Pacific, off Ecuador SEPBOP, R/V Anton Bruun: cruise 18B, sta 770 (USNM 1207983). A, shield and cephalic appendages, dorsal; B, right antennal peduncle, lateral; C, sternum and coxae of first to fifth pereopods, and anterior portion of pleon with first gonopods, ventral; D, exopod of left uropod, dorsal; E, telson, dorsal; F, left first gonopod, mesial; G, left second gonopod, anterior. Scale bars = 1 mm (A, C); 0.5 mm (B, E, F); 0.25 mm (D).

Fig. 22. Oncopagurus elongatus, new species: A, B, E, holotype, female 4.0 mm, Vanuatu, MUSORSTOM 8, sta CP 1080 (MNHN- IU-2013-5497); C, D, paratype, male 3.0 mm, French Polynesia, BENTHAUS, sta DW 2020 (MNHN-IU-2013-5508, ex MNHN Pg 6724). A, right cheliped, dorsal; B, chela of same, mesial; C, right cheliped, dorsal; D, chela of same, mesial; E, left cheliped, dorsal. Scale bar = 1 mm.

Fig. 23. Oncopagurus elongatus, new species: A–E, G, holotype, female 4.0 mm, Vanuatu, MUSORSTOM 8, sta CP 1080 (MNHN- IU-2013-5497); F, paratype, male 3.0 mm, French Polynesia, BENTHAUS, sta DW 2020 (MNHN-IU-2013-5508, ex MNHN Pg 6724). A, right first ambulatory leg, lateral; B, dactyl of same, mesial; C. right second ambulatory leg, lateral; D, dactyl of same, mesial; E, F, propodus and dactyl of left fourth pereopod, lateral. Scale bars = 1 mm (A–D); 0.25 mm (E–G).

Fig. 27. Oncopagurus minutus (Henderson, 1896): male 2.5 mm, New South Wales, Australia (AM P40409). A, shield and cephalic appendages, dorsal; B, right ocular peduncle, lateral; C, right cheliped, dorsal; D, chela of same mesial; E, dactyl of first ambulatory leg, mesial; F, propodus and dactyl of left fourth pereopod, lateral; G, telson, dorsal; H, left first gonopod, mesial; I, left second gonopod, anterior. Scale bars = 1 mm (A, C–E), 0.5 mm (B, F–I)). [Adapted from Lemaitre (1996)].

Fig. 24. Oncopagurus glebosus Lemaitre, 1997, paratype, male 2.3 mm, Indonesia, KARUBAR, sta CP 86 (USNM 276036). A, shield and cephalic appendages, dorsal; B, right ocular acicle, lateral; C, right cheliped, dorsal; D, E, chela of same, ventral (D), and lateral (E); F, right second ambulatory leg, lateral; G, dactyl of same, mesial; H, propodus and dactyl of left fourth pereopod, lateral; I, telson, dorsal; J, left first gonopod, mesial; K, left second gonopod, anterior. Scale bars = 1 mm (A, C–E, F, G), 0.25 mm (B, J, K), 0.5 mm (H, I). [Adapted from Lemaitre (1997)].

Fig. 40. Oncopagurus rossanae, new species, A, B, D, holotype, male 2.9 mm, French Polynesia, Austral Islands, BENTHAUS, sta DW 1973 (MNHN-IU-2013-6869); C, paratype female 2.0 mm, French Polynesia, Austral Islands, BENTHAUS, sta DW 1905 (USNM 1207998, ex MNHN Pg 6692): A, right cheliped, dorsal; B, chela of same, ventral; C, carpus and chela of right cheliped, dorsal; D, left cheliped, dorsal. Scale bars = 1 mm (A, B, D); 0.5 mm (C).

Fig. 2. Oncopagurus bifidus, new species, Philippines: A–F, holotype, male 3.4 mm, MUSORSTOM 3, sta CP 96 (MNHN-IU-2013-5584, ex MNHN Pg 7569); G, paratype, ov female 2.8 mm, same sta (MNHN-IU-2013-5583, ex MNHN Pg 7569); H, paratype, male 2.4 mm, sta CP 72 (MNHN-IU-2013-5491, ex MNHN Pg 7577). A, shield and cephalic appendages, dorsal; B, right antennal peduncle, lateral; C, epistome, laterodorsal; D, right cheliped of male, dorsal; E, right cheliped of female, dorsal; F, chela of same, mesial; G, left cheliped, dorsal; H, left second gonopod, lateral. Scale bars = 1 mm (A, D–G); 0.5 mm (B); 0.25 mm (C).

Fig. 5. Oncopagurus bifidus, new species, Philippines: A–C, holotype, male 3.4 mm, MUSORSTOM 3, sta CP 96 (MNHN-IU-2013-5584, ex MNHN Pg 7569); D, E, paratype, ov female 2.8 mm, same sta (MNHN-IU-2013-5583, ex MNHN Pg 7569). A, sternum and coxae of first to fifth pereopods, ventral; B, exopod of left uropod, dorsal; C, telson of male, dorsal; D, E, telson of female, dorsal (D) and posterior (E). Scale bars = 1 mm (A); 0.5 (D, E); 0.5 mm (B, C).

Fig. 36. Oncopagurus pollicis, new species, holotype, male 3.2 mm, New Caledonia, CHALCAL 2, sta DW 72 (MNHN-IU-5496):A, right cheliped, dorsal; B, chela of same, ventral; C, dactyl, fixed finger, and distal portion of palm of right cheliped, ventral; D, left cheliped, dorsal; E, same lateral. Scale bars = 1 mm (A, B, D, E); 0.5 mm (C).

Fig. 45. Oncopagurus spiniartus, new species, holotype, male 2.3 mm, southern Indian Ocean, Île Amsterdam and Île St.-Paul, CENTOB, MD 50, DC 82, sta 19 (MNHN-IU-5494, ex MNHN Pg 7610): A, right first ambulatory leg, mesial; B, same, lateral; C, right second ambulatory leg, lateral, D, dactyl of same, mesial. Scale bars = 1 mm (A–D); 0. 5 mm (E, F).

Fig. 8. Oncopagurus brevis, new species, holotype, male 3.2 mm, Hawaiian Islands (BPBM S10992). A, right cheliped, dorsal; B–D, chela of same, ventral (B), lateral (C), mesial (D); E, merus of right cheliped, mesial; F, left cheliped, dorsal. Scale bar = 1mm.

Fig. 6. Oncopagurus brevis, new species, A–F, holotype, male 3.2 mm, Hawaiian Islands (BPBM S10992); G, paratype, male 3.0 mm, same station as holotype (BPBM S10992). A, shield and cephalic appendages, dorsal; B, right antennal peduncle, lateral; C, anterior and posterior lobes of thoracic sternite XII (between second ambulatory legs), ventral; D, exopod of left uropod, dorsal; E, telson, dorsal; F, left second gonopod, anteromesial; G, right second gonopod, lateral. Scale bars = 1 mm (A); 0.5 mm (B–G).

Fig. 30. Oncopagurus orientalis (de Saint Laurent, 1972), Indonesia, KARUBAR, sta CP 35 (MNHN Pg 5353): A–D, F–H, female 2.2 mm; I, J, male 2.5 mm. A, shield and cephalic appendages, dorsal; B, right cheliped, dorsal; C, D, chela of same, ventral (C), mesial (D); E, chela of holotype, ventral; F, left second ambulatory leg, lateral; G, propodus and dactyl of right fourth pereopod, lateral; H, telson, dorsal; I, J, male second right (I) and left (J) gonopods, lateral. Scale bars = 1 mm (A, B–F), 0.5 mm (G–J). [Adapted from de Saint Laurent (1972) and Lemaitre (1997)].

Fig. 49. Oncopagurus stockmani Zhadan, 1997, ov female 7.0 mm, eastern Pacific, off Más a Tierra Island, Juan Fernández Islands, SEPBOP, R/V Anton Bruun, cruise 12: sta 65–MV–IV–54 (USNM 1211233): A, right first ambulatory leg, lateral; B, dactyl of same, mesial; C, right second ambulatory leg, lateral; D, dactyl of same, mesial; E, propodus and dactyl of left fourth pereopod, lateral; F, propodus and dactyl of left fifth pereopod, lateral. Scale bars = 2 mm.

Fig. 18. Oncopagurus elevatus, new species, A–D, F, holotype, male 3.8 mm, SMIB 3, sta DW 1 (MNHN-IU-2013-5515); E, paratype, female 3.0 mm, CHALCAL 2, sta DW 72 (MNHN-IU-2013-5516). A, right cheliped, dorsal; B, C, chela of same, lateral (B), mesial (C); D, E, carpus and chela, ventral; E, carpus and chela. Scale bars = 1 mm.

Fig. 50. Oncopagurus tuamotu (Lemaitre, 1994), French Polynesia: A–F, holotype female 3.7 mm, Tuamotu, Tureia (MNHN Pg 5153); G, H, paratype male 3.4 mm, Austral Islands (MNHN Pg 5154). A, shield and cephalic appendages, dorsal; B, right cheliped, dorsal; C, chela of same, ventral; D, dactyl of left second ambulatory leg, mesial; E, propodus and dactyl of left fourth pereopod, lateral; F, telson, dorsal; G, male left second gonopod, anterior; H, male right second gonopod, anterior. Scale bars = 3 mm (A–D); 1 mm (E–H). [Adapted from Lemaitre (1994)].

Fig. 28. Oncopagurus monstrosus (Alcock, 1894): A–D, H–L, lectotype, male 4.2 mm, Bay of Bengal (USNM 156566); E, female 3.4 mm, Indonesia (USNM 168939); F, male 4.2 mm, Indonesia (USNM 168940); G, male 5.1 mm, Philippines (USNM 168931). A, shield and cephalic appendages, dorsal; B, carpus and chela of right cheliped, dorsal; C, D, chela of same, lateral (C), mesial (D); E, right cheliped of female, dorsal; F, G, chela of male, ventral; H, dactyl of right first ambulatory leg, mesial; I, propodus and dactyl of left fourth pereopod, lateral; J, telson, dorsal; K, left first gonopod, mesial; L, left second gonopod, anterior. Scale bars = 1 mm (A, H); 2 mm (B–G); 0.5 mm (I–L). [Adapted from Lemaitre (1996)].

Fig. 29. Oncopagurus oimos Lemaitre, 1998, holotype, male 2.8 mm, French Polynesia, Moruroa atoll (MNHN Pg 5505). A, shield and cephalic appendages, dorsal; B, right cheliped, dorsal; C, chela of same, ventral; D, first left ambulatory leg, lateral; E, second left ambulatory leg, lateral; F, dactyl of same, mesial; G, propodus and dactyl of left fourth pereopod, lateral; H, telson, dorsal; I, left second gonopod, lateral; J, left second pleopod, lateral. Scale bars = 1 mm (A–E), 0.5 mm (F–H, I, J). [Adapted from Lemaitre (1998)].