Afrolaophonte koreana, Karanovic, 2022

Karanovic, Tomislav, 2022, A new species of Afrolaophonte (Copepoda, Harpacticoida, Laophontidae) from Korea and cladistic tests of species-groups, Journal of Species Research 11 (4), pp. 239-252 : 240-245

publication ID	https://doi.org/ 10.12651/JSR.2022.11.4.239
persistent identifier	https://treatment.plazi.org/id/03DE87BC-3901-FFB1-FC8E-FC89FA51F85A
treatment provided by	Felipe
scientific name	Afrolaophonte koreana
status	sp. nov.

Treatment

Afrolaophonte koreana View in CoL sp. nov.

( Figs. 1-4 View Fig View Fig View Fig View Fig )

Type locality. South Korea, South Sea , Dangdong, small beach, intertidal sand, interstitial water from a Karaman-Chappuis hole, 34°59.629 ʹ N 128°26.201 ʹ E GoogleMaps .

Specimens examined. Holotype female and allotype male, dissected on one slide each, both collected from the type locality, 4 April 2012, leg. T. Karanovic.

Paratype male in alcohol, collected from South Korea, South Sea, Busan, Songjeong Beach, intertidal sand, interstitial water from a Karaman-Chappuis hole, 35°10.741 ʹ N 129°12.317 ʹ E, 6 May 2016, leg. T. Karanovic GoogleMaps .

Etymology. The species name refers to South Korea. It is an adjective, agreeing in gender with the feminine genus name.

Description. Holotype female. Total body length, measured from tip of rostrum to posterior margin of caudal rami (excluding caudal setae and appendages) about 500 μm. Colour of preserved specimens yellowish. Nauplius eye not visible. Prosome comprising cephalothorax with completely fused first pedigerous somite and three free pedigerous somites; urosome comprising six urosomites; although second and third urosomites fused into genital double-somite, original segmentation still visible in dorsal and lateral views. Habitus ( Fig. 1A- C View Fig ) vermiform, slightly tapering posteriorly, not particularly slender, without distinct demarcation between prosome and urosome, prosome slightly shorter than urosome, cephalothorax about 1.15 times as wide as genital double-somite in dorsal view. Body length/width ratio about 5.6. Integument of all somites relatively well sclerotized, generally coarse but clean (with hardly any bacterial growth, mucus, or accumulated sediment), and without cuticular windows. Hyaline fringe of all somites relatively narrow; that of cephalothorax smooth, those of other somites finally serrated on lateral and dorsal sides. Minute spinules present on all somites except on cephalothorax, their frequency and size increasing towards posterior end. Cuticular sensilla present on all somites except fifth urosomite (preanal somite), their number generally decreasing towards posterior end, with 32 pairs on cephalothorax (including one pair on rostrum), six on first free prosomite, eight on second free prosomite, seven on third free prosomite, six on first urosomite, three on second urosomite, five on third urosomite, three on fourth urosomite, and one on sixth urosomite (anal somite). Cuticular pores not present, except one pair on caudal rami.

Rostrum ( Fig. 1A, C View Fig ), small, demarcated at base, triangular but with lateral notches at insertion of sensilla, about half as long as first segment of antenulla.

Cephalothorax ( Fig. 1A- C View Fig ) about 1.2 times as long as wide, slightly tapering towards anterior end in dorsal view, with pronounced ventro-lateral wings of tergites midlength partly covering mouth appendages.

Pleurons of free prosomites and first urosomite short, with convex sides, widely spaced, with short pseudosomites between them.

Genital double-somite ( Figs. 1A, B View Fig , 2A View Fig ) slightly wider than long in ventral view, with posterior ventro-lateral corners expanded into small rounded wings, each with one large sensilla and several large spinules; posterior margin in ventral view with row of hair-like spinules.

Fourth urosomite ( Figs. 1A, B View Fig , 2A View Fig ) about half as long as genital double-somite, half as long as wide in ventral view, with similar ventro-lateral wings as in genital double-somite, and also with posterior row of hair-like spinules on ventral side.

Fifth urosomite ( Fig. 2A View Fig ) only slightly shorter than fourth urosomite, without ventro-lateral wings, but with posterior row of hair-like ventral spinules.

Sixth urosomite ( Figs. 1A, B View Fig , 2A View Fig ) 1.2 times as long as fifth urosomite, covered with minute spinules on all sides and larger spinules along anal operculum and posterior margin on ventral side; anal operculum convex, very short and narrow.

Caudal rami ( Fig. 2A View Fig ) only about half as long as sixth urosomite, nearly cylindrical (although slightly tapering towards posterior end), covered with minute spinules on all sides, with one ventral cuticular pore and six setae (three lateral, one dorsal, and three terminal); dorsal seta slender and smooth, about 1.4 times as long as ramus, inserted at 2/3 of ramus length; two proximal lateral setae inserted very close to each other at about 3/4 of ramus length, ventral one minute (shorter than most sensilla), dorsal one slender and smooth, 1.1 times as long as ramus; distal lateral seta also slender and smooth, insert- ed at about 4/5 of ramus length, as long as ramus; innermost terminal seta smooth, slender, about 0.65 times as long as ramus; outermost terminal seta strong, pinnate, with breaking plane, about three times as long as ramus; central terminal seta strongest, smooth, with breaking plane, about ten times as long as.

Antennula ( Fig. 3A View Fig ) about half as long as cephalothorax, five-segmented, with several rows of minute spinules on first segment, recurved caudal cuticular beak on second segment, long and slender aesthetasc on fourth segment, and setal formula 1.9.5.2.12; aesthetasc fused at base with one long seta and three apical setae on fifth segment also fused at base; six lateral setae on fifth segment biarticulate (inserted on short pseudojoint), all other setae uniarticulate; second segment longest while fourth segment shortest.

Antenna ( Fig. 3C View Fig ) comprising coxa, allobasis (fused basis and first endopodal segment), one-segmented endopod, and much smaller but also one-segmented exopod; coxa very short, slightly wider than long, unarmed, and unornamented; allobasis cylindrical, almost twice as long as wide and nearly three times as long as coxa, unornamented, with single short seta in distal half; endopod about as long as allobasis but significantly narrower, with narrower base than distal part, with one anterior row of large spinules, one distal surface frill, one smooth and short lateral spine, slender and smooth seta on posterior surface flanked by lateral spine, and six smooth apical elements (three of them geniculate setae, longest one fused at base to slender seta); exopod also with slightly narrower base than distal part, 0.3 times as long as endopod, three times as long as wide, with longitudinal row of minute spinules and four pinnate setae.

Labrum ( Fig. 1C View Fig ) trapezoidal, rigidly sclerotized, with slightly convex cutting edge, with numerous slender apical and subapical spinules, those in central part of cutting edge longest.

Mandibula ( Fig. 3D View Fig ) small, heavily chitinized, composed of large curved coxa and small palp; palp one-segmented, cylindrical, 2.8 times as long as wide, with two minute smooth lateral setae and one longer but also smooth apical seta; cutting edge of coxa narrow, with one large ventral tricuspidate tooth, one smooth dorsal seta, and four unicuspidate teeth in between.

Maxillula ( Fig. 3E View Fig ) slightly larger than mandibula, composed of praecoxa, coxa, basis, and minute exopod; endopod completely fused with basis and probably represented by single bare seta; praecoxa large, quadrate, unornamented; praecoxal arthrite mobile, with row of anterior spinules in proximal half, five strong and unipinnate apical spines, one ventral smooth spine, and two smooth and slender anterior setae; coxa represented by very small, unornamented endite, with one long unipinnate spine and one smooth seta; basis more than twice as long as coxal endite, slender, tapering distally, unornamented, about 2.5 times as long as wide, with one unpinnate spine (shorter than that on coxa) and one smooth

A seta on endite in addition to endopodal smooth seta; exopod with single smooth seta.

Maxilla ( Fig. 3F View Fig ) about as large as maxillula, composed of large syncoxa with two endites and small basis (exopod reduced without trace, while endopod probably represent- ed by single seta); syncoxa ovoid, with heavily chitinized outer half and weakly chitinized inner half, with outer row of large spinules and inner row of smaller spinules; proximal endite short, with two strong unipinnate setae; distal endite twice as long as proximal endite, with two strong pinnate setae and one minute smooth seta; basis elongate, fused with strong apical spine into claw-like structure, unornamented, with three smooth setae.

Maxilliped ( Fig. 3G View Fig ) twice as long as maxilla, slender, prehensile, three-segmented, composed of syncoxa, basis, and one-segmented endopod; syncoxa 2.5 times as long as wide, with single short seta on inner-distal corner; basis 1.7 times as long as syncoxa, nearly four times as long as wide, unarmed and unornamented; endopod minute, fused completely with apical claw-like spine, unornamented; apical spine nearly as long as basis.

First swimming leg ( Figs. 1C View Fig , 3H View Fig ) long and slender, composed of minute praecoxa, large coxa, short and wide intercoxal sclerite, large basis, short one-segment- ed exopod, and long and prehensile two-segmented endopod; praexoca triangular, unarmed and unornamented; coxa trapezoidal, with two rows of large spinules, unarmed; basis pentagonal, somewhat smaller than coxa, with one row of spinules, one inner seta, and one outer seta; exopod cylindrical, shorter than basis, about 2.8 times as long as wide, unornamented, with two outer spines and two apical seta (outer apical seta geniculate); first endopodal segment longest, about five times as long as exopod, 5.4 times as long as wide, unarmed and unornamented; second endopodal segment slightly longer than exopod, with two rows of large spinules, one short and smooth seta and long and curved apical spine; apical endopodal spine about 2.5 times as long as second endopodal segment.

Second swimming legs ( Figs. 1C View Fig , 4A View Fig ) small, fused medially, each simple bilobate cuticular plate, with slen- der outer basal seta on long setophore and two apical spines (outer one shorter) and single innermost minute seta as only remnants of exopodal armature; distal lobe (probably ancestral exopod) with minute spinules along inner and outer margins; endopod reduced without any trace.

Third swimming legs ( Figs. 1C View Fig , 4C View Fig ) slightly bigger than second legs, also fused medially, but with distinct one-segmented exopod and endopod represented by small lobe; slender outer basal seta on long setophore; endopodal lobe with single apical spiniform seta; exopod slightly more than twice as long as wide, with five spines (proximalmost longest) and innermost slender and short seta; exopod and basal setophore with several rows of minute spinules.

Fourth swimming leg ( Figs. 1C View Fig , 4E View Fig ) significantly larg- er than third leg but with same segmentation; endopodal lobe larger than in third leg and with two slender plumose setae; exopod about 4.4 times as long as wide, with six long and plumose armature elements (four outer spines and two apical setae); basal setophore, endopodal lobe and exopod with several rows of slender spinules.

Fifth legs ( Fig. 4G View Fig ) similar in size and segmentation to fourth legs but not fused medially; exopod ovoid, shorter than in fourth leg, 2.2 times as long as wide, with long and selender spinules along outer and distal margins but with smooth inner margin, with four long and plumose setae; endopodal lobe larger than in fourth leg, with two inner short unipinnate spines, and two long plumose apical setae (inner one almost twice as long as outer one).

Sixth leg ( Fig. 2A View Fig ) minute cuticular flap covering go- nopore, with single smooth seta about as long as smaller sensilla.

Male. Body length about 400 μm. Second and third urosomites not fused, but habitus shape ( Fig. 1D View Fig ), ornamentation of somites ( Fig. 2B View Fig ), caudal rami ( Fig. 2C View Fig ), rostrum ( Fig. 3B View Fig ), antenna, mouth appendages, and first swimming leg as in female.

Antennula ( Fig. 3B View Fig ) seven-segmented, prehensile, slightly larger than in female; first two segments and sev- enth segment very similar to female; third segment short, as well as fifth and sixth, while fourth segment largest, ovoid, with basal notch; only aesthetasc on fourth segment slightly shorter and wider than in female; seta formula 1.9.5.8.0.1.10; two setae on basal notch of fourth segment spiniform (one smooth, other unipinnate), all others smooth and slender.

Second swimming leg ( Fig. 4B View Fig ) slightly smaller than in female, but with similar segmentation, armature, and ornamentation.

Third swimming leg ( Fig. 4D View Fig ) similar in size to female, but with three-segmented exopod and one-segmented endopod; endopod conical, 1.25 times as long as endopod, unornamented, with two inner smooth and short setae; first and second exopodal segments quadriform, each with single short outer spine (that on first segment longer); third exopodal segment about twice as long as second exopodal segment, with three short spines and single innermost slender and short seta.

Fourth swimming leg ( Fig. 4F View Fig ) much smaller than in female, without endopodal lobe, and with three segmented exopod; first and second exopodal segments quadriform, each with single strong outer spine (that on first segment longer, recurved, and especially strong); second exopodal segment with three strong spines and single innermost slender and short seta.

Fifth legs ( Fig. 4H View Fig ) much smaller than in female, fused medially, unornamented, without endopodal lobe, with basal seta on long setophore, and three setae on minute exopod.

Sixth legs ( Fig. 4I View Fig ) fused fused medially into simple cuticular flap with two smooth setae on each corner.

Variability. Paratype male from Busan was only examined in toto and at lower magnification (63 × objective), but was no different from the allotype in any characters .