Delavalia californiensis Gómez 2021, sp. nov.
Creators: name: Gómez, Samuel
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Hexanauplia
Harpacticoida
Miraciidae
Delavalia
Delavalia californiensis

description: Delavalia californiensis sp. nov.
(Figs. 7–13)
urn:lsid:zoobank.org:act: 7D066388-03A8-486F-BF01-6AE89C760433
Type locality. Off La Bocana, Baja California Sur (Eastern Tropical Pacific), Mexico; Talud XV cruise, sampling station 20 (26.5428°N, 113.9389°W); depth 479 m; organic carbon content, 3.18%; organic matter content, 5.47%; sand 47.08%; clay, 7.75%; silt, 45.16 %.
Specimens examined. Adult female holotype dissected (habitus left intact) and mounted onto 15 slides (EMUCOP-020812-04), and adult male allotype dissected partially as follows: antennules, rostrum, and P2–P4 dissected and mounted onto four slides, the rest left intact and preserved in alcohol (EMUCOP-020812-05); August 2, 2012; coll. S. Gómez.
Etymology. The specific epithet with the Latin suffix –ensis, pertaining to, alludes the region where the species was found. It is in the nominative singular. Gender feminine.
Description of female. Total body length measured from tip of rostrum to posterior margin of caudal rami, 650 µm; habitus pyriform, widest at posterior end of cephalothorax, tapering posteriad (Fig. 7A); cephalothorax/body length ratio, 0.35.
Cephalothorax and free pedigerous somites (Fig. 7A) largely as in previous species.
Urosome (Fig. 7A–C) as in previous species.
Fifth pedigerous somite (Fig. 7A–C) narrower than preceding somites; without spinular ornamentation.
Second and third urosomites completely fused dorsally and ventrally forming genital double-somite (Fig. 7C), with dorsolateral trace of division (Fig. 7A–B); genital double-somite as long as wide, widest part measured in anterior fourth close to P6; proximal half of genital double-somite with dorsal (Fig. 7A) and lateral sensilla (Fig. 7B), ventrally without sensilla (Fig. 7C), without spinular ornamentation (Fig. 7A–C); distal half of genital doublesomite with dorsal and lateral sensilla and dorsolateral spinular rows (Fig. 7A–B), ventrally with few sensilla and without spinules (Fig. 7C); posterior hyaline fringe broad and smooth; genital complex hardly distinguishable, copulatory pores not exposed, paired genital apertures located ventrolaterally and covered by P6 (Fig. 7C).
Fourth urosomite (Fig. 7A–C) as distal half of genital double-somite, with two ventral pores (Fig. 7C).
Fifth urosomite without sensilla nor spinules (Fig. 7A–C), with two ventral pores.
Anal somite three times as wide as long (Fig. 7A), with spinules around joint of caudal rami laterally (Fig. 7B) and ventrally (Fig. 7C), with spinules along medial cleft ventrally, with one lateral and two ventral pores on each side (Figs. 7A–C); anal operculum without spinular ornamentation, semicircular, flanked by one sensilla on each side (Fig. 7A).
Caudal rami elongate, about 6.5 times as long as wide (Figs. 7A–C) and about 2.8 times as long as anal somite; with outer spinules at base of setae I and II, and with inner subdistal spinules (Fig. 7A–D), with one proximal outer and one subdistal inner pore; with seven elements (Fig. 7D); setae I and II issuing at subdistal outer margin, closely set, the former spine-like and ventral to seta II, the latter lost during dissection; seta III subdistal, arising ventrally (Fig. 7B–D); setae IV and seta V distal, posterior half of the former rat-tail like in distal half, the latter broken off; seta VI small, issuing at inner distal corner; dorsal seta VII triarticulate at base, situated subdistally close to inner margin.
Rostrum (Fig. 8A) trapezoidal, not fused to cephalothorax, bifid, with two subdistal sensilla, without dorsal pore.
Antennule (Fig. 8A) eight-segmented; all segments smooth, except for first segment with proximal spinular row; first segment without pore. All setae smooth, except for one pinnate seta on first and second segments; second segment with one, third segment with one (or two?) setae with fracture plane; seventh segment with one, eighth segment with two articulated setae. Armature formula: 1(1); 2(11); 3(8); 4(4 + (1 + ae)), 5(3); 6(4); 7(4); 8(5 + acro). Acrothek consisting of two setae and one minute aesthetasc fused basally.
Antenna (Fig. 8B). Coxa short, with some outer spinules. Allobasis as long as free endopodal segment; with two inner spinular rows below the insertion site of abexopodal seta, and one outer spinular row proximally; with one abexopodal seta arising midway inner margin. Free endopodal segment elongate; proximal half with longitudinal row of inner spinules, with subdistal outer strong spinules, with two outer subdistal frills; lateral armature composed of two spines and two setae, distal armature composed of one inner geniculate apical element, three apical pinnate geniculate setae and one slender element, and one outer distal pinnate geniculate element fused basally to slender seta. Exopod three-segmented; first and third segments longest; first and middle segments without, third segment with subdistal spinules; first and second segments with one distal seta each, third segment with one proximal and three apical setae, two of which seemingly fused basally.
Mandible (Fig. 9A). Coxa relatively short. Gnathobase wide; ventral distal corner produced into small sharp semi-hyaline process; with two strong and several smaller teeth, two spines and two setae, one of which pinnate. Basis elongate, with small spinules proximally, medially and subdistally as shown, with three subdistal outer setae. Exopod arising from short pedestal, one-segmented, elongate, about 3.5 times as long as wide, and 0.4 times as long as basis; with three lateral and three apical setae, none of which fused basally. Endopod recurved, twisted over exopod; with three lateral setae, and five distal elements (three slender setae, one of which spinulose and one strong element, and longest element fused to endopod basally and with hyaline flange in middle part).
Maxillule (Fig. 9B). Arthrite of praecoxa with two surface setae and some dorsal spinules proximally; distal armature composed of nine elements, of which two setiform and one spinulose element, two spiniform with a long spinule, and one lateral spinulose recurved seta. Coxal endite with three setae; with subdistal spinules. Basis with two endites; proximal endite with four, distal endite with three slender setae. Exopod and endopod fused basally, separated from basis, one-segmented; endopod larger than exopod, with four setae; exopod small, with two setae.
Maxilla (Fig. 9C). Large syncoxa with some outer spinules as shown; with three endites; proximal endite bilobed, each lobe with two setae; middle and distal endites elongate, the latter slightly longer, with three spinulose setae each. Basis drawn out into strong claw, with strong spinulose spine and two slender setae, one of which arising from elongate setophore. Endopod one-segmented, with six slender setae (one arising basally, two medially, and three apically).
Maxilliped (Fig. 9D) subchelate. Syncoxa rectangular, about two times as long as wide; with medial and inner spinules as shown; with one bare and two spinulose strong elements, of which bare seta and one spinulose element at the same level, the other arising distally from long pedestal. Basis slightly shorter than syncoxa, oval, with some outer spinules, with one anterior and one posterior inner spinular row as depicted, with two slender distal setae subequal in length. Endopod one-segmented, with one claw-like element and one seta.
P1(Fig.10A).Intercoxal sclerite(not shown)transversely elongate,nearly straight,without surface ornamentation. Coxa massive, 1.3 times as wide as long, with one outer proximal, one outer subdistal, and one medial subdistal row of spinules. Basis with outer and inner spinulose spines, with spinules at base of endopod and at base of inner spine. Exopod three-segmented, longer than endopod; no pores detected on exopodal segments; EXP1 longest, EXP3 shortest; all segments without outer nor inner acute distal processes; EXP1 and EXP2 with longitudinal row of outer spinules; EXP1 without, EXP2 with inner seta; EXP3 with longitudinal row of outer spinules, with two outer spines and two apical setae, the latter rat-tail like in distal half. Endopod two-segmented, reaching distal third of EXP2, segments without inner nor outer acute distal processes; no pores detected on endopodal segments; ENP1 reaching slightly beyond tip of EXP1, 1.7 times as long as wide, visibly longer than ENP2, with outer and distal spinules, and slender medial inner spinules as shown, with one inner long seta; ENP2 small, rectangular, about 1.7 times as long as wide, and 0.5 times as long as ENP1, with small spinules at base of outer element, with three distal elements, of which outermost a spine, medial a long rat-tail like strongly plumose seta, innermost a slender seta.
P2–P4 (Figs. 10B, 11A–B). Intercoxal sclerite (not shown) not transversely elongate, trapezoidal, with strong pointed process on distal outer corners, without surface ornamentation. Praecoxa small, without spinular ornamentation. Coxa with outer spinules proximally and subdistally. Basis with (P2) or without spinules (P3 and P4) at base of outer seta, with strong acute process between rami and at inner distal corner, the latter larger, of P2 largest, of P4 smallest. Exopod three-segmented, of P2 reaching middle of ENP3, of P3 slightly shorter than ENP, of P4 visibly longer than ENP; no pores detected on exopodal segments; EXP1 and EXP2 with outer acute distal process (of P4 less developed), with longitudinal row of outer spinules and with inner distal frill, with inner seta; EXP3 with distal processes as shown, with few outer spinules proximally, with three outer spines and two apical setae, of P2 with two, of P3 and P4 with three inner setae. Endopod three-segmented, of P2 visibly longer than, of P3 slightly longer than EXP, of P4 reaching proximal third of EXP3; pores present on P2 ENP2 and P3 ENP3; P2–P4 ENP1–3 with longitudinal row of outer spinules; P2 and P3 ENP1 and ENP2 with inner distal spinules, P4 ENP1 without, ENP2 with inner distal spinules; P2–P4 ENP1 shortest, ENP3 longest; ENP1 and ENP2 with outer acute and inner small distal process, outer process of ENP2 visibly longer, distal processes of ENP3 as shown; ENP1 with inner element, of P2 and P3 a slender short seta, of P4 a long stiff element with inner margin pinnate; ENP2 with two (P2) or one inner seta (P3 and P4); ENP3 with one apical outer spine, two apical elements, and one (P2), three (P3) or two (P4) inner setae.
Setal formula of swimming legs as follows:
P5 (Fig. 11C). Baseoendopod pentagonal; endopodal lobe poorly-developed, with five setae, of which outermost shortest and set closely to adjacent seta, all setae pinnate. Exopod oval, with six setae and few outer spinules as shown.
P6 (Fig. 7C) represented by a minute flap covering ventrolateral genital aperture; fused to somite, without surface ornamentation, with one slender seta.
Description of male. Total body length measured from tip of rostrum to posterior margin of caudal rami, 700 µm; general shape of habitus (Fig. 12A) as in female.
Sexual dimorphism expressed in the antennule, genital somite and third urosomite not fused, P2 ENP, P5 and P6.
Pedigerous somites largely as in female.
Genital somite and third urosomite not fused (Fig. 12A–B), each with dorsolateral spinules and with posterior sensilla dorsally (Fig. 12A); ventral surface of genital somite without spinular ornamentation, of third urosomite with continuous transverse row of spinules and some sensilla (Fig. 12B).
Fourth urosomite with dorsolateral spinules and sensilla as shown (Fig. 12A), ventrally with medial transverse spinular row and few sensilla, with two pores (Fig. 12B).
Fifth urosomite as preceding somite but without lateral and dorsal spinular ornamentation (Fig. 12A), and ventral spinular row shorter (Fig. 12B).
Anal somite and caudal rami (Fig. 12A–B), and rostrum (not shown) as in female.
Antennule (Fig. 13A) ten-segmented; haplocer; with geniculation between fourth and fifth, and seventh and eighth segments; first segment without pore. All segments smooth except for seventh segment with some spinules —no spinular ornamentation detected on first segment. All setae smooth except for pinnate long seta on first segment and short element on fifth segment. Second and third segments with one seta with fracture plane each; seventh segment with one, ninth and tenth segments with two articulated setae. Aesthetasc present on third, fifth, and last segments. Armature formula: 1(1); 2(13); 3(7 + ae); 4(1); 5(8 + (1 + ae)), 6(1); 7(1); 8(1); 9(4); 10(5 + acro). Acrothek consisting of two setae fused basally to aesthetasc.
Antenna, mandible, maxillule, maxilla and maxilliped, P1, P3, and P4 (not shown) as in female.
P2 EXP (not shown) as in female; P2 ENP (Fig. 13B) sexually dimorphic, two-segmented; first segment small, with inner and outer process, with longitudinal row of outer spinules and inner distal row of minute spinules, with one inner seta; second segment elongate, with one medial pore, with three inner setae as shown, distal part bifurcate with outer small notch (see insert of Fig. 13B).
P5 (Figs. 12B, 13C). Both legs fused medially forming a continuous plate; endopodal lobe poorly-developed, with two pinnate setae, of which outermost smaller; EXP small, oval, with five elements (one outer spine like element, two apical outer slender setae, one apical inner pinnate strong and long element, and one inner visibly shorter pinnate seta).
P6 (Figs. 12B, 13D) asymmetrical, one leg functional, the other fused to somite; each leg with outer basal seta and two elements, of which innermost a spine, outermost a slender long seta.
Variability. No variability was detected in the single female and male found in the sediment samples.
description: Published as part of Gómez, Samuel, 2021, On some deep-sea Stenheliinae from the Gulf of California and the west coast of the Baja California Peninsula (Mexico): the genus Delavalia Brady, 1869 and proposal of Archaeohuysia gen. nov. and Diarthropodella gen. nov. (Copepoda Harpacticoida: Miraciidae), pp. 171-235 in Zootaxa 5051 (1) on pages 180-189, DOI: 10.11646/zootaxa.5051.1.12, http://zenodo.org/record/5563569