Kalloleptochelia multiarticulata, Tzeng & Wei & Ma & Li, 2023

Tzeng, You-Wei, Wei, Chih-Lin, Ma, Lin & Li, Xinzheng, 2023, Three new species of Paratanaoidea (Crustacea, Tanaidacea) from the South China Sea, Zootaxa 5375 (1), pp. 1-30 : 14-19

Kalloleptochelia multiarticulata sp. nov.

Figs 7–9 , Table 2

Material examined. Holotype: male ( MBM287539 ), body length 2.1 mm, completely dissected and body parts preserved in 75% alcohol, West Sand (16°58’39.7”N, 112°12’43.8”E), Xisha Islands , the South China Sea, intertidal, washing from algae turf and bottom sand, 8 July 2019.

Paratypes: male ( MBM287540 ), body length 2.6 mm, Tree Island (16°58’46.6”N, 112°16’18.9”E), Xisha Islands , the South China Sea, intertidal, washing from algae turf and bottom sand, 8 July 2019 .

Diagnosis. Male: Body about 5.8 times longer than wide. Carapace as long as pereonites 1–3 combined. Antennule flagellum slightly longer than peduncle article-1, ten to eleven-articled, each article with two distal aesthetascs except last article. Antenna article-2 dorsal margin with one subdistal seta, inner surface with two distal setae, ventral margin with one distal seta; article-3 dorsal margin with one long spiniform seta. Cheliped 0.8 times as long as body; carpus 5.3 times longer than wide, with three dorsal and three ventral setae; propodus inner setal row with 16 setae, fixed finger incisive margin with ten conical denticles and about three inconspicuous denticles, dactylus incisive margin with seven conical denticles and nine spinules. Pereopod-1 dactylus and unguis combined slightly longer than propodus, unguis 0.7 times as long as dactylus. Pereopods 2–3 dorsal margin with one subdistal seta. Pereopod-6 merus ventral margin with two distal spiniform setae, carpus distal margin with two outer and three inner spiniform setae. Uropod exopod two-articled, endopod six-articled.

Description (some characters stated in diagnosis not included). Male (holotype): Habitus ( Fig. 7A, B , 8A ) dorsoventrally flattened, 2.1 mm long. Carapace oval-shaped, 0.2 times as long as body 1.4 times longer than wide; rostrum wide and rounded; lateral margin with one pair of middle setae. Eye lobe large and well developed, with visual elements. Pereon 0.6 times as long as body; pereonites 1–3 relatively short, 0.4, 0.5, 0.5 times as long as wide, respectively, each with one pair of anterolateral setae; pereonite-4 1.8 times longer than pereonite-3 0.8 times as long as wide, lateral margin with one subanterior seta; pereonite-5 0.8 times as long as pereonite-4 0.7 times as long as wide, lateral margin with two setae on posterior half; pereonite-6 0.8 times as long as pereonite-5 0.6 times as long as wide, with one pair of anterolateral and one pair of posterolateral setae. Pleon 0.2 times as long as body; pleonite-1 0.2 times as long as wide, with one pair of lateral setae; pleonites 2–4 0.2 times as long as wide each, each with two pairs of lateral setae; pleonite-5 narrowest, 0.3 times as long as wide, with two pairs of lateral setae. Pleotelson 0.4 times as long as wide, lateral margin with two setae, posterior margin with three pairs of setae and one pair of broom setae.

Antennule ( Fig. 8B ) 0.6 times as long as body; peduncle 0.6 times as long as antennule, three-articled, article-1 about as long as carapace, four times longer than wide, with two proximal broom setae, two distal setae and three distal broom setae, article-2 half as long as article-1 four times longer than wide, with two distal setae and two distal broom setae, article-3 0.4 times as long as article-2 twice as long as wide, with one distal seta; flagellum article- 1 short, with two ventrodistal aesthetascs, distal article extremely short, cap-like, with two setae, the remaining articles each with two ventrodistal aesthetascs.

Antenna ( Fig. 8C ) six-articled; article-1 short, ventral margin with one distal seta; article-2 as long as wide, dorsal margin with one subdistal seta, inner surface with two distal setae, ventral margin with one distal seta; article- 3 short, dorsal margin with one long distal spiniform seta; article-4 longest, 1.5 times longer than article-2, with one proximal broom seta, two middle setae and one middle broom seta, two subdistal setae and four subdistal broom setae; article-5 0.8 times as long as article-4, with two distal setae and one distal broom seta; article-6 very short, cap-like, with five long and one short setae.

Mouthparts reduced; rudimentary maxilliped and epignath not examined.

Cheliped ( Fig. 8D ) long and slender; coxal sclerite triangular, with one seta on middle of outer surface; basis 1.8 times longer than wide, with one outer seta; merus subtrapezoidal, half as long as basis, ventral margin with one long and two short setae, inner surface with one distal seta; carpus 2.1 times longer than basis, dorsal margin with three short setae on proximal half, ventral margin with three longer setae on distal half; propodus palm and fixed finger combined as long as carpus, palm 3.5 times longer than wide, dorsal margin with one short distal seta, inner setal row ( Fig. 8E ) with 16 setae, outer surface with one distal seta between dactylus and fixed finger, fixed finger ( Fig. 8E ) curved, 0.7 times as long as palm, incisive margin with ten conical denticles and about three inconspicuous denticles, with five setae one distal half, unguis presence; dactylus ( Fig. 8E ) curved, about as long as fixed finger, incisive margin with alternate seven conical denticles and nine spinules, unguis present.

Pereopod-1 ( Fig. 8F ) coxa with one seta; basis 4.3 times longer than wide, dorsal margin with one seta and one broom seta on proximal half; ischium with one ventral seta; merus 0.4 times as long as basis 1.9 times longer than wide, dorsal and ventral margin both with one subdistal seta; carpus about as long as merus, with four subdistal setae; propodus long, 1.7 times longer than carpus 4.4 longer than wide, dorsal margin with two subdistal setae, ventral margin with one subdistal seta; dactylus and unguis long and slender, dorsal margin with one long proximal seta.

Pereopod-2 ( Fig. 8G ) coxa with one seta; basis 4.2 times longer than wide, dorsal margin with one seta and two broom setae on proximal half; ischium with one ventral seta; merus 0.4 times as long as basis 1.9 times longer than wide, dorsal margin with one subdistal seta, ventral margin with one thin distal spiniform seta; carpus as long as merus, dorsal margin with one distal seta, ventral margin with one subdistal seta and subdistal spiniform seta; propodus 1.5 times longer than carpus 4.1 longer than wide, dorsal margin with two subdistal setae, ventral margin with one subdistal spiniform seta; dactylus plus unguis half as long as propodus, with one middle transversal row of setules.

Pereopod-3 ( Fig. 8H ) similar to pereopod-2 but basis with one broom seta on proximal margin, without simple seta; ischium with two ventral setae; carpus with two distal spiniform seta on inner surface; propodus with one less subdistal seta on dorsal margin.

Pereopod-4 ( Fig. 9A ) basis 3.1 times longer than wide, ventral margin with one middle broom seta; ischium with two ventral setae; merus 0.4 times as long as basis twice as long as wide, ventral margin with two strong distal spiniform setae; carpus about as long as merus 2.3 times longer than wide, distal margin with two outer and two inner strong spiniform setae, and one simple seta; propodus 1.4 times longer than carpus about five times longer than wide, dorsal margin with three subdistal serrated setae, ventral margin with two thin subdistal spiniform setae; dactylus plus unguis falciform, half as long as propodus.

Pereopod-5 ( Fig. 9B ) very similar to pereopod-4 but basis more swollen, 1.9 times longer than wide, dorsal margin with one simple seta on distal half, ventral margin with one simple seta and two broom setae.

Pereopod-6 ( Fig. 9C ) very similar to pereopod-5 but basis 2.4 times longer than wide, dorsal margin with two broom setae on proximal half, ventral margin with two setae, without broom seta; carpus distal margin with three inner spiniform seta.

Pleopod-3 ( Fig. 9D ; all setae circumplumose, setules omitted in figure) peduncle with one inner circumplumose seta; exopod with 18 outer circumplumose setae; endopod with twelve outer circumplumose setae, inner margin with one middle circumplumose seta.

Uropod ( Fig. 9E ) peduncle with six distal setae; exopod article-1 short, with one distal seta, article-2 with two long distal setae; endopod article-1 with seven distal and subdistal setae, and one broom seta, article-2 similar to article-1, article-3 with three distal setae, article-4 with five distal setae and two distal broom setae, article-5 with one distal seta, article-6 with four distal setae.

Variations. The holotype male ( MBM287539 ) possesses a ten-articled flagellum on its left antennule, but the right antennule flagellum unexamined (missing). The paratype male ( MBM287540 ) possesses a ten-articled flagellum on its left antennule and eleven on its right.

Etymology. The name is from the Latin multi (many) and articulus (article), referring to the greatest number of articles of male antennule flagellum in the genus.

Type locality. Xisha Islands, the South China Sea.

Distribution. It is only known from the South China Sea.

Remarks. The new species, K. multiarticulata sp. nov., can be easily differentiated from its congeners by four exclusive male characters, of which: 1) presence of ten to eleven articles on antennule flagellum (versus eight or less articles in congeners); 2) presence of one subdistal seta on dorsal margin of pereopods 2–3 merus (versus absent in congeners); 3) presence of five distal spiniform setae on pereopod-6 carpus (versus four or less in congeners); 4) presence of a two-articled exopod on uropod (versus one in congeners; Guţu 2011: fig 9A, C, D, F; Guţu 2016: figs 42A, B, D, 43B, C, F, 44A, B, E, F, H, I, 45A, B, F, H, I; Figs 8A, B, G, H , 9C, E ; Table 2 ).

Figures

FIGURE 7. Kalloleptochelia multiarticulata sp. nov. specimens (ethanol-preserved), photo by You-Wei Tzeng. Holotype (MBM287539), male: A, dorsal view (with a support); B, lateral view.

FIGURE 8. Kalloleptochelia multiarticulata sp. nov. Holotype (MBM287539), male:A, body dorsal view; B, left antennule; C, right antenna (outer view); D, left cheliped; E, left cheliped propodus and dactylus inner view; F–H, right pereopods 1–3.

FIGURE 9. Kalloleptochelia multiarticulata sp. nov. Holotype (MBM287539), male:A, right pereopods 4–6; D, right pleopod- 3 (all setae circumplumose, setules omitted); E, right uropod.