Argestes analongises, Gómez, 2018

Gómez, Samuel, 2018, Two new deep-sea species of Argestidae and Ameiridae (Copepoda: Harpacticoida) from the Eastern Mexican Pacific and Gulf of California, with proposal of a new genus of the family Argestidae, Journal of Natural History 52 (41 - 42), pp. 2613-2638: 2616-2621

publication ID 10.1080/00222933.2018.1546915

publication LSID

persistent identifier

treatment provided by


scientific name

Argestes analongises

sp. n.

Argestes analongises   sp. n.

( Figures 1 – 6 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 )

Material examined

Female holotype (ICML-EMUCOP-230800-01) dissected and mounted onto seven slides; Talud IV cruise; 23 August 2000; coll   . S   . Gómez.

Type locality

Off Nayarit State, NW Mexico, few miles north of Islas Marías (22°01 ʹ 2 ʺ N, 106°40 ʹ 2 ʺ W), 1540 m depth GoogleMaps   .

Diagnosis (based on the female only)

Posterior margin of second urosomite to anal somite smooth, with spinules dorsally and ventrally. Genital somite and third urosomite distinct. Anal somite slightly longer than two preceding somites combined, tapering distally; anal operculum shifted medially. Caudal rami four times as long as wide, with six setae. Antennule seven-segmented. Antenna with allobasis, with one-segmented exopod bearing one seta. Mandibular palp biramous. Syncoxa of maxilla with two endites; proximal (praecoxal) endite with one, distal (coxal) endite with three elements. P2 – P4 with three-segmented rami. Syncoxa of

maxilliped with two setae. P1 EXP1 without, P2 – P4 EXP1 with inner seta; P1 – P4 EXP2 with inner seta; P1 – P4 EXP3 with five, seven, eight, and seven setae/spines, respectively; proximal inner seta of P4 EXP3 reduced, spiniform. P1 – P4 ENP1 – 2 with inner seta; P1 ENP3 with three, P2 – P4 ENP3 with five setae/spines. P5 endopodal lobe poorly developed, with two setae; P5 EXP elongated, with six setae.

Description of female

Body. Total body length undetermined due to bad condition of the only specimen; subcylindrical, tapering slightly posteriorly. Second to fifth urosomite with small surface spinules dorsally ( Figure 1 View Figure 1 (a)) and ventrally ( Figure 1 View Figure 1 (b)) as figured; posterior margin with continuous transverse row of strong spinules dorsally; sensilla along posterior margin of somites arising from small tubercles. Genital somite with transverse row of minute spinules along posterior margin ventrally; third urosomite with continuous row of visibly less strong spinules ventrally; fourth urosomite with lateroventral transverse row of visibly less strong spinules, with row of strong spinules midventrally; fifth urosomite with strong spinules ventrally as shown.

Anal somite ( Figure 1 View Figure 1 (a,b)). Tapering posteriorly, slightly longer than two preceding somites combined, posterior margin medially cleft; dorsal ( Figure 1 View Figure 1 (a)) and ventral ( Figure 1 View Figure 1 (b)) surface covered with spinules as figured; anal operculum shifted rather medially, ornamented with two transverse rows of spinules, and flanked by one seta on each side.

Caudal rami ( Figure 1 View Figure 1 (a,b)). Cylindrical, elongated, four times as long as wide (width measured at widest distal part), covered with spinules as shown, with six setae, all issuing distally, as follows: seta I lost; homologation of setae II and III difficult, probable seta II arising on outer distal corner, seta III shifted ventrally; setae IV and V longest; seta VI issuing at inner distal corner; dorsal seta VII subdistally, tri-articulated, arising from small tubercle.

Antennule ( Figure 2 View Figure 2 (a)). Seven-segmented; all segments covered with minute denticles; first, and third-fifth segments with medium to small sized spinules, second segment with medium sized spinules proximally and subdistally, and with set of stronger and longer medial spinules; sixth and seventh segments without spinular ornamentation; sixth segment with very long single naked seta distally. Armature formula as follows: 1-[1se], 2-[4sp+ 5se], 3-[2sp+ 5se], 4-[1sp+ 1se+(1se+ ae)], 5-[1sp+ 1se], 6[1sp+ 2se], 7-[1sp+ 2se+ 6 art+ acro].

Antenna ( Figure 2 View Figure 2 (b)). Allobasis elongated, as long as free endopodal segment, with suture indicating original division between basis and first endopodal segment, without abexopodal seta, with inner longitudinal row of spinules. Exopod one-segmented, with one seta. Endopod with inner longitudinal row of strong spinules, with smaller spinules on surface and with stronger ones subdistally, with few outer spinules; with two inner lateral spines medially, and with six elements apically (three single geniculated setae, one geniculate seta fused basally to small naked element, and one slender seta).

Mandible ( Figure 3 View Figure 3 (a)). Gnathobase with acute tooth-like projections. Palp biramous, covered with spinules; basis with one pinnate seta, and one strong flame-shaped spine; endopod with one inner, three subapical and two apical pinnate setae; exopod visibly smaller, with three bipinnate setae.

Maxillule ( Figure 3 View Figure 3 (b)). Praecoxal arthrite with row of spinules proximally, with two surface setae, one lateral pinnate spine, and seven distal spines of which two single and bare, two with articulated tip and bare, and three pinnate elements of which two with long spinules and one with small spinules. Coxa with one subdistal seta, and apically with one slender seta and one very strong, pinnate element. Basis with some median

and some subdistal spinules, with two apical setae. Endopod fused to basis, represented by two setae. Exopod one-segmented, elongated, with two bipinnate setae.

Maxilla ( Figure 3 View Figure 3 (c)). Syncoxa with spinules as shown; with two endites; proximal (praecoxal) endite small, with one slender seta; distal (coxal) endite with one strong spinulose element fused to endite, and two bare setae. Allobasis with spinules proximally and at base of strong spinulose claw, the latter fused to allobasis, and with one strong spine. Endopod represented by two setae.

Maxilliped ( Figure 3 View Figure 3 (d)). Subchelate, strong. Syncoxa with inner long and outer small spinules as shown, with two bipinnate setae subequal in length. Basis unarmed, with inner and outer longitudinal rows of spinules. Endopod one-segmented, fused to strong spinulose claw, with one accompanying bare seta.

P1 ( Figure 4 View Figure 4 (a)). Coxa with small spinules close to inner corner proximally, and medially close to basis, the latter with inner and outer spiniform elements, with some spinules in the middle, at the base of endopod, and at the base of outer element. Endopod three-

segmented, visibly longer than exopod; ENP1 and ENP2 with inner seta; ENP3 with three elements, outermost a spine. Exopod three-segmented; EXP1 without, EXP2 with inner seta; EXP3 with five elements.

P2–P4 ( Figures 4 View Figure 4 (b), 5(a–c)). Coxa and basis covered with detritus, making spinular ornamentation difficult to see. Coxa with anterior set of strong spinules close to distal outer corner, and with additional small spinules close to proximal outer corner, posteriorly with longitudinal row of long, slender outer spinules. Basis of P2 and P3 with long slender inner spinules, with small spinules at base of endopod and at base of outer seta, of P4 with comparatively shorter inner spinules, and with spinules at base of endopod and at base of outer seta; outer basal seta of P2 spiniform, of P3 and P4 slender and long. Endopod three-segmented, reaching middle of EXP3; ENP1 and ENP2 with inner seta; ENP3 with two inner and two apical setae, and one outer spine. Exopod three-segmented; EXP1 and EXP2 with inner seta; P2 EXP3 with three outer, two apical and two inner elements, P3 EXP3 with three outer, two apical and three inner elements; of P4 with three outer, two apical and two inner elements, of which proximal reduced, spine-like.

P5 ( Figure 6 View Figure 6 ). With some spinules on baseoendopodal setophore. Endopodal lobe poorly developed, with two setae subequal in length, with some slender, long spinules between both baseoendopods. Exopod distinct, elongated, slender, four times as long as wide (maximum width measured at its base), with spinules as figured, with six setae.