Asterocheres fici, Lee, 2024

Lee, Il-Hoi Kim and Taekjun, 2024, Copepods of the genus Asterocheres Boeck, 1859 (Siphonostomatoida: Asterocheridae) from Korean waters, Journal of Species Research 13 (2), pp. 185-254 : 220-224

publication ID	https://doi.org/ 10.12651/JSR.2024.13.2.185
persistent identifier	https://treatment.plazi.org/id/ED1887CB-FFDD-FFCC-FF41-B113B269643D
treatment provided by	Felipe
scientific name	Asterocheres fici
status	sp. nov.

Treatment

Asterocheres fici n. sp. ( Figs. 21-23 View Fig View Fig View Fig )

https://zoobank.org/urn:lsid:zoobank.org:act:4F413855-

A915-47CE-BB95-0B9D58B8C50F

Type material. Holotype (intact ♀; MABIK CR0025 4668), intact paratypes (12♀♀, 2♂♂; MABIK CR00 254669), and dissected paratypes (2♀♀, 1♂) from washing of the sponge, Suberites ficus (Johnston, 1842) , as a fishery bycatch, at Kisamoon fishing port, Yangyang, Gangwon-do (38°00 ʹ 44 ʺ N, 128°43 ʹ 48 ʺ E), shallow subtidal, coll. I.-H. Kim, 07 October 2011 GoogleMaps . Holotype and intact paratypes has been deposited in the Marine Biodiversity Institute of Korea ( MABIK), Seocheon. Dissect- ed paratypes are kept in the collection of I-H. Kim .

Etymology. The name of the new species is taken from the specific name of the host, Suberites ficus .

Female. Body ( Fig. 21A View Fig ) relatively large. Body length of dissected and described specimen 1.07 mm. Prosome broad, 737× 596 μm. All prosomal somites with round- ed lateral corners. Urosome ( Fig. 21B View Fig ) 4-segmented. Fifth pedigerous somite 170 μm wide, bearing minute spinules scattered on lateral and dorsal surfaces. Genital double-somite slightly wider than long (144 × 152 μm), widest at proximal fourth, gradually narrowing posteriorly from widest region; genital apertures positioned dorsolaterally at anterior third; postgenital lateral margin bearing about 26 spinules consisting of 17 longer but thinner anterior spinules and 9 shorter but thicker posterior spinules ( Fig. 22F View Fig ). Genital double-somite and first free abdominal somite bearing fine spinules along posterodorsal and posteroventral margins. Two free abdominal somites 44 × 82 and 56 × 73 μm, respectively. Anal somite bearing spinules along posteroventral margin ( Fig. 21C View Fig ). Caudal ramus ( Fig. 21C View Fig ) 1.10 times longer than wide (34 × 31 μm), armed with 6 setae, and ornamented with 2 long spinules on subdistal outer margin and spinules and 1 small tube pore on posteroventral margin.

Rostrum ( Fig. 21D View Fig ) strongly tapering, with rounded distal apex. Antennule ( Fig. 21E View Fig ) 483 μm long, 21-segmented; segments each bearing 2 setae, except 8 setae on 9th segment, 2 setae + aesthetasc on 18th segment, 4 setae on penultimate segment, and 7 setae on terminal segment; some of setae on proximal segments pinnate or truncated and tipped with minute setule. Antenna ( Fig. 21F View Fig ) as usual for genus; first endopodal segment 85 μm long; terminal claw spiniform, 113 μm long, 1.33 times longer than first endopodal segment.

Oral siphon ( Fig. 21G View Fig ) 259 × 91 μm, evenly tapering, extending between maxilliped and leg 1. Mandible ( Fig. 21H View Fig ) with slightly curved coxal stylet of 273 μm long, distally bearing 12 teeth (not including terminal dentiform point); palp 87 μm long, 1-segmented but with obscure trace of segmentation at distal fourth, tipped with 2 unequal, pinnate setae (220 and 109 μm long, respectively); palp plus longer distal seta 307 μm long, 1.12 times longer than stylet. Maxillule ( Fig. 21I View Fig ) bilobed; inner lobe about 98 μm long, armed distally with 4 long and 1 small setae (lengths of 4 longer setae 167, 159, 152, and 98 μm, respectively); outer lobe small, 33 μm long, armed with 3 long weakly pinnate setae and 1 short naked seta (lengths of these setae 128, 105, 80, and 18 μm, respectively). Maxilla ( Fig. 21J View Fig ) bearing row of spinules proximally on proximal segment; tube of maxillary gland rather distinct; distal segment distinctly longer than proximal segment, bearing tuft of setules and row of spinules. Maxilliped ( Fig. 21K View Fig ) 6-segment- ed, with armature formula 1, 1, 2, 1, 1, and 1 + claw; inner seta on basis rudimentary; basis and first endopodal segment bearing row of spinules on outer margin; third endopodal segment bearing 1 spinule on outer margin; terminal segment and claw 57 and 117 μm long, respectively.

Legs 1 ( Fig. 22A View Fig ), 2 ( Fig. 22B View Fig ), 3, and 4 ( Fig. 22D View Fig ) segmented and armed as usual for genus. Intercoxal plate of legs 1-3 bearing spinules. Inner coxal seta of leg 1 thin, short, and naked. Inner coxal seta of leg 4 also small and naked. Outer margin of coxa of legs 1-4 covered with spinules. Leg 3 endopod ( Fig. 22C View Fig ) differ from that of leg 2 in having 1 spine and 5 setae on third segment. Distal spine on third endopodal segment of leg 4 68 μm long, slightly shorter than segment (76 μm long). Armature formula for legs 1-4 as in A. aesthetes .

Leg 5 ( Fig. 21B View Fig ) consisting of 1 pinnated dorsolateral seta on fifth pedigerous somite and exopod; exopodal segment 2.83 times longer than wide (68 × 24 μm), with 3 setae and nearly parallel outer and inner margins, both margins densely covered with spinules; 3 setae 69, 50, and 28 μm long, respectively, from outer and inner; 2 distal setae pinnate; subdistal inner seta naked, with annulation proximally. Leg 6 ( Fig. 22F View Fig ) represented by 1 pinnate seta and 1 spinules on genital operculum.

Male. Body ( Fig. 23A View Fig ) narrower and smaller than that of female. Body length 800 μm in dissected specimen. Prosome 545 × 409 μm. Urosome ( Fig. 23B View Fig ) 5-segment- ed. Fifth pedigerous somite 110 μm wide. Genital somite subcircular, wider than long (127 × 144 μm), laterally covered with fine spinules. Genital operculum well-developed, bearing spinules on outer and inner margins and 10-12 setules on inner margin ( Fig. 23G View Fig ). Three abdominal somites 22 × 67, 18 × 58, and 36 × 56 μm, respectively. Caudal ramus as long as wide (25 × 25 μm).

Rostrum as in female. Antennule ( Fig. 23C View Fig ) 18-segmented; 9th, 13th, 16th, 17th, and terminal segments bearing 7 setae, 2 setae + aesthetasc, 3 setae, 5 setae + aesthetasc, and 10 setae, respectively; all other segments each with 2 setae; anterodistal corner of 17th segment produced with pointed tip. Antenna as in female.

Oral siphon, mandible, maxillule, and maxilla as in female. Maxilliped with proximal process on inner margin of basis, otherwise as in female.

Third endopodal segment leg 2 ( Fig. 23D View Fig ) with slightly curved outer distal process and spinulose distal margin. Third endopodal segment of leg 3 ( Fig. 23E View Fig ) with slightly curved outer distal process; distal seta on same segment small, much shorter than distal spine.

Exopodal segment of leg 5 ( Fig. 23F View Fig ) 2.60 times longer than wide (39 × 15 μm), with 3 pinnate setae; lengths of these setae 49, 41, and 23 μm, respectively, from out- er to inner. Leg 6 ( Fig. 23G View Fig ) represented by 2 unequal pinnate seta and pointed process on posterolateral corner of genital operculum.

Remarks. Three species of Asterocheres may be compared with A. fici n. sp., as they reveal relatively high similarity values with the new species, sharing at least 11 of 15 character states with the new species ( Table 2). These three species ( A. corneliae ; A. flustrae Ivanenko & Smurov, 1997 ; and A. latus (Brady, 1872)) can be distinguished from the new species by their following differences from the new species:

In A. corneliae the oral siphon is slender, as figured in the original description by Schirl (1973), the mandibular stylet bears three thick and several minute teeth, according to Bandera & Conradi (2016) (cf. 12 almost identical teeth in the new species), and the setae of the outer lobe of the maxillule are short, not extend beyond the distal tip of the inner lobe (cf. longer, extends beyond the distal tip of the inner lobe in the new species).

In A. flustrae the oral siphon extends to the base of the maxillipeds, the mandibular palp is 2-segmented, and the sexual dimorphisms of the swimming legs are different from those of the new species, as described and illustrated by Ivanenko & Smurov (1997).

In A. latus , as redescribed by Bandera & Conradi (2009b), the caudal ramus is 2.6 times longer than wide and the mandibular palp is 2-segmented.

The small, naked inner seta on coxa of leg 1, the elongate exopodal segment of female leg 5 which is densely ornamented on the parallel inner and outer margin, the characteristic forms, and ornamentations of endopods of male legs 2 and 3 and male genital operculum may allow the new species to be easily identified.