Phoxokalliapseudes cinctus, Wi, Jin Hee, Kang, Chang-Keun & Soh, Ho Young, 2017

Wi, Jin Hee, Kang, Chang-Keun & Soh, Ho Young, 2017, Two new species in the genus Phoxokalliapseudes Drumm & Heard, 2011 (Crustacea: Tanaidacea: Kalliapseudidae) from the southwestern and southern coasts of Korea, Zootaxa 4231 (3), pp. 341-363 : 351-361

Phoxokalliapseudes cinctus n. sp.

( Figs 7–12 )

Materials examined. Holotype: ( MABIK IV 00155516 ) female dissected and mounted on five slides; collected from the southern coast of Korea (34˚32.9´N; 128˚ 34.6´E at a depth of 47 m) in April 2016.

Allotype: ( MABIK IV 00155514 ) male dissected and mounted on five slides; from the same locality as the holotype .

Paratypes: one female partly dissected on one slide (MABIK IV00155517); from the same locality as the holotype. One male partly dissected on one slide ( MABIK IV 00155515 ) ; from the same locality as for holotype.

Diagnosis. Rostrum rounded. Cephalothorax almost as long as wide and with three mid-lateral setae. Pereonites 2–6 each with hyposphaenium. Pleonites 1 to 5 with ventral process. Pleotelson with two long plumose setae on indented tip. Pleotelson with two long plumose setae and two short simple setae on indented tip. Accessory flagellum of antennule with four articles in female and five articles in male. Antenna first article with five distal plumose setae on medial extension. Mandible setiferous lobe with five distal setae. In cheliped, basis with two strong spiniform setae on ventral margin and length-to-width ratio of propodus 2.5: 1 in male. Female pereopod 6 dactylus 3.1 times as long as propodus. Male pereopod 6 dactylus 4.3 times as long as propodus.

Etymology. The specific name is derived from the Latin noun cinctus , ‘crown’ or ‘garland’, referring to the crown-like setules on the distal margin of the two coupling hooks of the maxilliped endite.

Description of female: Body ( Fig. 7 A): 5.8 ~ 6.3 mm long, 5.3 times as long as wide. Cephalothorax 17% of body length, almost as long as wide, with one simple seta on proximolateral margin and three simple setae on midlateral margin, rostrum rounded. Pereon: 48% of body length. Pereonites 2–6 each with ventral shape similar to female. Pereonite 1 0.3 times as long as wide, proximal lateral margin wider than cephalothorax, with three slender setae on proximolateral margin and two simple setae on distolateral margin. Proportional lengths of pereonites 1–6 10.2: 16.4: 18: 21.7: 22.2: 11.5. Pereonites 1–6 with two slender setae on dorsoproximal margin. Pleonites 1–5: 23% of body length, 1.3 times longer than wide, with two slender setae on dorsoproximal margin, several plumose setae along lateral margin, and ventral process. Pleonites 3–5 equal in length. Pleotelson: 12% of body length, half as long as pleonites 1–5 combined, with one mid-lateral seta, one distolateral seta, two dorsoproximal setae, and with two short simple setae and two long plumose setae on distal margin. Distal margin rounded.

Antennule ( Fig. 7 B): first peduncle article 2.4 times as long as wide, with several broom setae and simple setae along inner and outer margins and with two spiniform setae of unequal length on subdistal margin. Second peduncle article 0.3 times as long as article 1, 1.5 times as long as wide, with two broom setae and several simple setae. Article 3 with two simple setae on inner distal margin. Article 4 0.6 times as long as article 3, with one inner distal seta. Outer flagellum as long as peduncle article 1, with ten articles: articles 5, 6, and 8 each with one aesthetasc. Inner flagellum with four articles, article 4 with three simple setae and one broom seta.

Antenna ( Fig. 7 C): medial extension of article 1 with five plumose setae on distal margin and third article with one plumose seta on distal corner.

Labrum ( Fig. 7 D): two distal cups of four hook-like cusps of clypeus smaller than proximal ones.

Mandible ( Fig. 8 A, B). Left mandible ( Fig. 8 A): incisor distally with seven denticles. Lacinia mobilis with six denticles. Right mandible ( Fig. 8 B): incisor with four denticles of different size (arrowed).

Labium ( Fig. 8 C): 1.4 times as long as wide, covered with setules.

Maxillule ( Fig. 7 E): inner endite with four setulose setae, with protrusion on mid–outer margin (arrowed). Outer endite with nine setulose setae and small naked seta on distal margin and two setulose setae on subdistal margin.

Maxilla ( Fig. 8 D): outer lobe of movable endite with five setulose setae; inner lobe of movable endite with twelve distally blunt spiniform setae. Outer lobe of fixed endite with four bi-serrated setae, eight distally blunt spiniform setae, and four plumose setae. Inner lobe of fixed endite with distal row of four bi-serrated spiniform setae, group of slender simple setae, and row of slender setae on subdistal margin. Inner margin with six spines and outer margin with slender setae and setules.

Maxilliped ( Fig. 8 E): basis fringed with plumose setae along outer margin and several microtrichia along inner margin. Palp article 1 with two setae each on inner and outer margins. Palp article 2 with two rows of long plumose setae along inner margin and three setae on outer distal margin. Palp articles 3 and 4 each bearing two rows of plumose setae along inner margin. Endite ( Fig. 8 E) with five short setulose setae and three long setulose setae on distal margin, eight setulose setae along inner margin, and two coupling hooks on inner margin of which distal margin ornamented with setules (arrowed in Fig. 8 F).

Cheliped ( Fig. 9 A): basis 2.1 times as long as wide, with two strong spiniform setae and two long simple setae on ventral margin. Merus with three simple setae on ventrodistal margin and one short simple seta on ventromedial margin. Carpus 4.4 times as long as wide. Propodus 1.2 times as long as carpus, three times as long as wide. Fixed finger with six simple setae near insertion of dactylus. Dactylus longer than fixed finger, with several spiniform setae along cutting edge and several setae on dorsal margin. Exopodite with two distal plumose setae.

Pereopod 1 ( Fig. 9 B): basis 1.7 times as long as wide, one simple spiniform seta and three simple setae on ventro-subdistal margin and several short simple setae along dorsal margin. Ischium with two ventrodistal simple setae. Dactylus with two simple setae of unequal length.

Pereopod 2 ( Fig. 10 A): basis 2.8 times as long as wide, with one broom seta and three simple setae on dorsal margin and three simple setae on ventral margin. Ischium with three simple setae on ventrodistal margin. Merus with one spiniform seta and two simple setae on ventrodistal margin. Carpus 1.4 times as long as merus, with three spiniform setae and three simple setae on ventral margin and one spiniform seta and four simple setae on outer subdistal margin. Propodus almost equal in length of carpus, with four spiniform setae and four simple setae on ventral margin, one broom seta and one spiniform seta with two processes at both sides of base on dorsal margin, one simple seta on subdistal surface, and four spiniform setae, with two simple setae on distal margin. Dactylus and unguis combined 2.3 times as long as propodus. Dactylus lacking sensory lobe. Unguis 2.6 times as long as dactylus.

Pereopod 3 ( Fig. 10 B): basis 2.4 times as long as wide, with two broom setae and one simple seta on dorsal margin and three simple setae on ventral margin. Ischium similar to pereopod 2. Merus shorter than that of pereopod 2, setae number equal to pereopod 2. Carpus 1.3 times as long as wide, with three spiniform setae and three simple setae on ventral margin and two spiniform setae and two simple setae on dorsal margin. Propodus shorter than that of pereopod 2, with four spiniform setae and four simple setae on ventral margin, one broom seta and one short spiniform seta bearing two processes proximally, and four spiniform setae and one simple seta on distal and sub-distal dorsal margins. Dactylus and unguis combined as long as that of pereopod 2. Dactylus lacking sensory lobe. Unguis 2.9 times as long as dactylus.

Pereopod 4 ( Fig. 10 C): basis twice as long as wide, with three broom setae and four simple setae on dorsal margin. Ischium with three simple setae on ventral margin. Merus with two spiniform setae and two simple setae on ventrodistal margin. Carpus 1.6 times as long as wide, with two rows of seven spiniform setae and several simple setae. Propodus 0.8 times as long as carpus, with two rows of seven spiniform setae, three simple setae, two short spiniform setae bearing two processes on proximal margin, and one dorsoproximal broom seta. Dactylus with several setae terminally.

Pereopod 5 ( Fig. 10 D): basis slightly longer than that of pereopod 4. Ischium, merus, and carpus similar to pereopod 4. Propodus with three spiniform setae bearing two proximal processes on dorsodistal margin.

Pereopod 6 ( Fig. 9 C): basis 3.6 times as long as wide, with five plumose setae each along ventral and dorsal margins. Ischium with three ventral simple setae of unequal length, with numerous patch of setules. Merus 1.1 times as long as ischium, with one simple seta ventrally and one plumose seta dorsally. Carpus 2.3 times as long as merus, 2.2 times as long as wide, with three simple ventral setae, one simple subdistal seta, and five plumose dorsal setae. Propodus 0.7 times as long as carpus, with four spiniform setae, row of 19 short setulose setae, and one distal blunt spiniform seta on ventral margin. Dactylus 3.1 times as long as propodus, with small simple seta subproximally and distally tapered.

Pleopod ( Fig. 10 E): basal article with three or four plumose setae on distal margin. Endopodite with 15 plumose setae. Endopodite with 20 plumose setae; distal region of innermost seta distally pointed, with one wrinkled spiniform seta and one simple seta.

Uropod ( Fig. 9 D): basal article 2.4 times as long as wide, with four simple setae distally, not extended to distal margin of pleotelson. Exopodite 0.7 times as long as basal article, with four simple distal setae. Endopodite with seven simple setae, minute simple seta, and one broom seta terminally.

Description of male: very similar to female except for following differences: Body ( Fig. 11 A): 4.7 times as long as wide. Cephalothorax 18% of body length, slightly wider than long. Pereon 46.1% of body length. Proportional lengths of pereonites 1–6 15.2: 17.2: 16.8: 23.6: 17.2: 10.0. Pleonites 1–5 proportional lengths of 16.7: 19.2: 20: 20.8: 23.3, respectively. Pleotelson 14.2% of body length, 0.6 times as long as pleonites 1–5 combined, with two mid-lateral setae, two distolateral setae, two dorsoproximal setae, and with two short simple setae and two long plumose setae on distal margin. Distal margin sub-rectangular.

Antennule ( Fig. 11 B): first peduncle article 41.8% of total length, 2.5 times as long as maximum width, with two spiniform setae of unequal length on subdistal margin, several broom setae and simple setae along inner and outer margins. Second peduncle article 0.2 times as long as proximal peduncle article, 1.2 times as long as wide, with several broom setae and simple setae. Article 3 0.6 times as long as article 2, with three distal setae. Article 4 0.8 times as long as article 3. Outer flagellum with eleven articles: articles 1–5 with bundle of aesthetascs, decreasing in number, articles 6, 7, and 9 with one aesthetasc and two simple setae on distal margin; article 11 with three simple setae and one broom seta on distal margin. Inner flagellum with five articles: articles 1–4 with one simple seta, article 5 with two distal simple setae.

Antenna ( Fig. 11 C): similar to that of female, but article 3 with two plumose setae on distal corner (arrowed).

Mandible ( Figs. 11 D, 12AE). Left mandible ( Fig. 11 D): incisor distally with ten denticles. Lacinia mobilis with five denticles. Right mandible ( Fig. 12 A): incisor with four denticles of different size.

Cheliped ( Fig. 12 B): basis 1.2 times as long as wide, with two strong spiniform setae. Merus similar to that of female. Carpus 3.8 times as long as merus, 3.4 times as long as wide. Propodus 1.1 times as long as carpus, 2.5 times as long as wide. Fixed finger with two small denticles (arrowed), one on palm margin and one on cutting edge and several setae, small denticles along cutting edge and eight simple setae along ventral margin. Dactylus longer than fixed finger, with several spiniform setae along cutting edge, and several setae on dorsal margin.

Pereopod 2: unguis 2.4 times as long as dactylus.

Character / Species name P. aculeatus P. cinctus P. gobinae Phoxokalliapseudes P. Phoxokalliapseudes P. P. tomiokaensis

n. sp. n. sp. (Bamber) cf. gobinae multiarticulus cf. multiarticulus singaporensis Drum and Heard (Guţu) Drum and Heard F M F M F M F M F F M M F M

Antennule

Number of articles on 6 5 4 5 6 4 4 8 6 6 5 6 5

accessory flagellum

Antenna

Number of setae on extension 7 7 5 5 - 7 - 6 - - 8 6 7 6 article 1

Number of setae on article 3 2 2 1 2 - 0 - 2 - - 3 1 2 2

Cheliped

Pereopod 3: basis 2.4 times as long as wide.

Pereopod 4: basis 2.7 times as long as wide.

Pereopod 5: similar to pereopod 4.

Pereopod 6 ( Fig. 12 C): basis and ischium similar to female. Merus 1.5 times as long as ischium, with one ventral simple seta and two dorsal plumose setae. Carpus similar to that of female. Propodus 0.6 times as long as carpus. Dactylus 4.3 times as long as propodus.

Uropod ( Fig. 12 D): 2.6 times as long as wide, with two simple setae on dorsal margin. Exopodite with seven simple setae, one short simple seta, and one broom seta terminally.

Remarks. Phoxokalliapseudes cinctus n. sp. can be differentiated from other species within Phoxokalliapseudes by the following morphological characters: in both sexes, 1) the proximal article of the antenna has five distal plumose setae on the medial extension; 2) in the maxilliped endite, two coupling hooks on the inner margin are ornamented along the distal margin and the distal margin has eight plumose setae; 3) pereopod 6 is ornamented with patches of minute setules on the ischium, merus, carpus, and propodus; 4) pereopods 2–6 each have one distal spiniform seta with a pair of processes on the propodus. 5) in the female, the ratio of the length of the dactylus to the propodus of pereopod 6 is the largest (3: 1). 6) in the male, the length-to-width ratio of the cheliped propodus is the largest (2.2: 1); 7) the cheliped fixed finger has a small triangular denticle on the cutting edge. In particular, the distal margin of the coupling hooks is surrounded with minute setules ( Fig. 8 F), which is a unique characteristic of P. cinctus ; the margin is simple in the other species of the genus. Additionally, sexual dimorphism was found in the antenna as a different number of setae on the third article (one in females and two in males), the shape of the cheliped fixed finger, the number of simple setae on the tip of the uropodal endopod (ten in females and seven in males), and the length of the dactylus of pereopod 6. In contrast to P. aculeatus , the number of setae on the setiferous lobe of the mandible and the number of seta on the inner lobe of the fixed endite of the maxilla was equal in both sexes.

Figures

FIGURE 7. Phoxokalliapseudes cinctus n. sp. female holotype. A, habitus, dorsal view; B, antennule; C, antenna; D, labrum; E, maxillule. Scale bars are given in mm.

FIGURE 8. Phoxokalliapseudes cinctus n. sp. female holotype. A, left mandible; B, right mandible; C, labium; D, maxilla; E, maxilliped; F, coupling hooks on endite. Scale bars are given in mm.

FIGURE 9. Phoxokalliapseudes cinctus n. sp. female holotype. A, cheliped; B, pereopod 1; C, pereopod 6; D, uropod. Scale bars are given in mm.

FIGURE 10. Phoxokalliapseudes cinctus n. sp. female holotype. A, pereopod 2; B, pereopod 3; C, pereopod 4; D, pereopod 5; E, pleopod; F, detailed view of proximal pleopod endopod seta. Scale bars are given in mm.

FIGURE 11. Phoxokalliapseudes cinctus n. sp. male allotype. A, habitus, dorsal view; B, antennule; C, antenna; D, left mandible. Scale bars are given in mm.

FIGURE 12. Phoxokalliapseudes cinctus n. sp. male allotype. A, right mandible; B, cheliped; C, pereopod 6; D, uropod. Scale bars are given in mm.