Jejulaophonte hyeopjaeensis, Back, Jinwook & Lee, Wonchoel, 2014

Back, Jinwook & Lee, Wonchoel, 2014, A new genus (Copepoda, Harpacticoida, Laophontidae) from Jeju Island of Korea, ZooKeys 447, pp. 1-20 : 3-9

Taxon classification Animalia Harpacticoida Laophontidae

Jejulaophonte hyeopjaeensis sp. n. Figs 1, 2, 3, 4, 5, 6, 7, 8

Type locality.

Intertidal zone at Hyeopjae beach Jeju island, Korea (33°23'41"N, 126°14'22"E) on 10 April 2004 (type specimen). For DNA analysis, specimens collected on 3 June 2010 (for DNA analysis) at type locality.

Material examined.

Holotype 1♀ (CR235161) dissected on 9 slides. Paratypes 1♂ (CR235162) dissected on 8 slides, and 11♀♀ (CR235163), 5♂♂ (CR235164) in 70% alcohol. 9 specimens (6♀♀, 3♂♂) dried, mounted on stubs, and coated with gold for SEM. All specimens are from the type locality.

Etymology.

Specific name refers the type locality of new species, Hyeopjae beach, Jeju Island, Korea.

DNA-barcode

(mt COI). Sequences and traces were submitted to GenBank (GenBank Accession numbers: KF857218, KF857219)

Description of female.

Total body (Fig. 1A, B) length from anterior margin of rostrum to posterior margin of caudal rami 477 µm (n = 6, mean = 472 µm). Maximum width 88 µm measured at midway of cephalothorax.

Body (Fig. 1A, B). Cylindrical and not dorsoventrally depressed with minute sensilla dorsally. Small sensilla well developed on the distal margin of prosomites and urosomites.

Rostrum (Fig. 1A). Diminutive, fused with cephalothorax, no sensilla.

Prosome (Fig. 1A). 4-segmented, comprising cephalothorax (bearing first pedigerous somite) and three free pedigerous somites. Cephalothorax subrectangular, wider than free somites. Cuticula between cephalothorax and first free somite distinctly pursed. Pleural areas of cephalic shield narrow and posterolateral angles rounded. Posterior margin of cephalothorax and all pedigerous somites with a row of long setules dorsally and laterally (Figs 1A, B, 8A). Free prosomites with spinules tuft on dorso-anterior surface and several setules on dorso-lateral margin.

Urosome (Fig. 1 A–C). 5-segmented, comprising P5-bearing somite, genital double-somite, and three free abdominal somites. Genital double-somite wide and original segmentation marked by a row of long setules and short spinules row arising from transverse surface ridge dorsally and laterally. Ventral surface bearing spinular tufts laterally. Each P6 (Fig. 2D) well developed opercula closing off paired genital apertures presented by one fig fused in middle, with 2 setae. Genital field (Figs 1C, 2D) located near the upper part of genital double-somite. Penultimate and anal somites distinctly narrow. Penultimate somite without sensilla dorsally. Anal somite with spinular tufts laterally; with well developed and smooth anal operculum (Figs 2C, 8H).

Caudal rami (Fig. 2C). Parallel, widely separated, dorsal surface with small minute spinules, and proximal inner margin with a lateral row of stout spinules. Each ramus with 7 setae: seta I smallest, setae II and III well developed and naked, seta IV naked, seta V longest and strongest, seta VI bare at the inner distal corner, seta VII naked and triarticulate at base.

Antennule (Fig. 2A). Slender, 6-segmented. Segment-2 with 1 small blunt process and 9 bare setae. Segment-4 carrying sub-cylindrical process furnished with 2 bare setae and 1 slender seta fused basally with aesthetasc. Apical acrothek consisting of an aesthetasc fused basally to 2 slender naked setae. Armature formula: 1-[1 bare], 2-[9 bare], 3-[6 bare], 4-[2 bare + (1+ae)], 5-[1 bare], 6-[9 bare + acrothek].

Antenna (Figs 2B, 8F). 3-segmented, comprising coxa, allobasis, and free 1-segmented endopod. Coxa small and bare. Allobasis with 1 bare abexopodal seta located about halfway along the segment. Exopod 1-segmented with 4 pinnate setae. Endopod, subtriangular pyramid-shaped, shorter than allobasis, spinule tuft on medial surface and with lateral armature consisting of 3 spines, 2 bare and 4 geniculate setae.

Labrum (Fig. 8B) with spinular ornamentation around distal margin; dense pattern of fine spinules anteriorly and distal patch of overlapping scales.

Mandible (Fig. 3A). Small gnathobase armed with 1 slender bare seta on dorsal side and several blunt teeth. Mandibular palp probably representing fused basis and endopod; with 1 lateral (basal) bare seta, 3 sub-distal bare setae, and 1 distal pinnate seta.

Maxillule (Figs 3B, 8B). Praecoxa trapezoidal shape armed with a few spinules around outer margin; Arthrite well-developed with 2 juxtaposed setae near halfway on anterior surface, 1 plumose seta laterally, and 8 elements around distal margin. Coxa bearing cylindrical endite with 2 bare setae. Basal endite with 3 distal naked setae. Exopod 1-segmented, armed with 1 distal naked seta and 1 short bared seta. Endopod incorporated into basis, forming small peduncle with 3 naked setae.

Maxilla (Figs 3C, 8B). Syncoxa without spinules on surface and armed with 2 slender endites. Proximal and distal endites armed with 1 spine and 2 setae. Allobasis produced into a strong curved claw; accessory armature consisting of 2 naked setae proximally and 1 pore distally. Endopod incorporated into allobasis, consisting of 2 bare setae fused basally and 1 small naked seta.

Maxilliped (Fig. 3D). 3-segmented. Syncoxa with 1 plumose seta. Basis elongate without ornamentation. Enodpod drawn out as a smooth claw with 1 accessory naked seta anteriorly.

P1 (Fig. 4A). Coxa ornamented with inner and outer spinules. Basis armed with 1 outer and 1 inner plumose setae. Exopod 2-segmented; exp-1 with 1 outer seta; exp-2 equal in length of exp-1, with 5 setae. Endopod 2-segmented; enp-1 over 3 times longer than exopod, longitudinal coarse spinules proximally; enp-2 (Fig. 8C) with 1 small accessory seta, 1 large strong claw, and ornamented with 4 big spinules arranged around distal inner margin.

P2 (Fig. 4B). Coxa with dense ornamentation on anterior surface and along outer margin. Basis with 1 outer plumose seta near outer distal corner. Exopod 3-segmented, about 2 times longer than endopod; exp-1 ornamented with spinules along lateral and anterior margin, setules along inner margin and 1 pinnate spine; exp-2 with 1 stout pinnate spine and spinules along outer margin; exp-3 with 3 elements. Endopod 2-segmented, enp-1 larger than enp-2; enp-1 without seta; enp-2 with 1 distal plumose seta.

P3 (Fig. 5A). Coxa with dense ornamentation on surface and along outer margin. Basis with 1 outer naked seta and ornamented with row of spinules on middle surface and along inner margin. Exopod 3-segmented; exp-1 armed with 1 strong outer spine; exp-2 with 1 inner and 1 outer setae; exp-3 with 2 inner, 2 distal, and 2 outer setae. Endopod 2-segmented, each segment furnished with a row of spinules on outer margin and long setules along inner margin; enp-1 without seta; enp-2 with 1 inner, 2 distal, and 1 outer setae.

P 4 (Fig. 5B). Coxa with a row of spinules along outer margin. Basis with 1 naked seta. Exopod 3-segmented, 2 times longer than endopod; exp-1 with 1 outer spine; exp-2 with 1 outer spine and 1 inner seta; exp-3 with 2 inner, 3 distal, and 2 outer setae. Endopod 2-segmented; enp-1 bare, ornamented with long setules on inner margin; enp-2 with 4 setae.

Armature formulae as follows:

P 5 (Fig. 5C). Baseoendopod ornamented with long setules along inner and outer margins and 1 basal naked seta. Endopodal lobe small, with 4 pinnate setae. Exopod oblong, with 5 plumose setae, a row of short spinules on outer margin and long setules along inner margin.

Description of male.

Body (Fig. 6A) cylindrical, more compact than in female; length 450 µm (n = 4, mean = 451 μm) measured from anterior margin of cephalic shield to posterior margin of caudal ramus. Maximum width 76 µm at posterior margin of cephalothorax.

General body shape, ornamentation and sensilla pattern as in female. Sexual dimorphisms in A1, P3, P4, P5, and P6.

Antennule (Figs 6 B–D, 8E). 7-segmented, robust, subchirocer. Segment-1 with 1 small seta on posterior margin. Segment-2 longest, with 1 small projection and 8 bare setae. Segment-5 with a proximal process anteriorly, and swollen. Segment-6 formed by 2 incompletely fused segments with 1 seta and 4 processes at inner margin. Distal position of segment-7 pointed, subtriangular, displacing acrothek to position isolated from other armature. Armature formula; 1-[1 bare], 2-[8 bare], 3-[5 bare], 4-[2 bare], 5-[17 bare + 1 modified + 1 pinnate + (1+ae)], 6-[1 + 4 processes], 7-[8 + acrothek]. Apical acrothek consisting of an aesthetasc and two naked setae.

Swimming legs 1-2 similar to those of female.

P3 (Figs 7A, 8D). Coxa with dense ornamentation on anterior surface. Basis with 1 naked outer seta. Exopod 3-segmented, more robust than in female; exp-1 ornamented with a row of spinules along inner and outer margin with 1 modified outer spine longer than female; exp-2 the shortest, with 1 outer, and 1 inner spine; exp-3 with 6 modified stout spines. Endopod 3-segmented; enp-1 ornamented a row of spinules on outer margin and long setules along inner margin, without seta; enp-2 with distal inner corner produced as an apophysis without ornamentation and 4 small processes on distal outer corner (Fig. 8D); enp-3 shortest, located next to apophysis of exp-2 with 1 inner and 2 distal setae.

P4 (Fig. 7B). Coxa with dense ornamentation on posterior surface. Basis with 1 naked outer seta. Exopod 3-segmented, exp-1 and exp-2 with modified outer spines; exp-3 with 6 modified spines. Endopod 2-segmented, enp-1 without seta; enp-2 with 1 outer, 2 apical, and 1 inner setae, all setae pinnate.

P5 (Fig. 7C). Fused medially; baseoendopod fig flattened, defined at the base. Baseoendopod with 1 outer basal seta, and endopodal lobe represented by 1 bare seta. Exopod small, with 1 bare, and 3 pinnate setae.

P6 (Fig. 7D, 8G). Symmetrical, represented on both sides by a small fig(fused to ventral wall of supporting somite along one side; articulating at base and covering gonopore along one side); outer distal corner produced into a cylindrical process with 1 inner pinnate and 1 outer naked setae.