Spaniomolgus stylophorus, Conradi, Mercedes, Bandera, Eugenia, Mudrova, Sofya V. & Viatcheslav N. Ivanenko,, 2018

Conradi, Mercedes, Bandera, Eugenia, Mudrova, Sofya V. & Viatcheslav N. Ivanenko,, 2018, Five new coexisting species of copepod crustaceans of the genus Spaniomolgus (Poecilostomatoida: Rhynchomolgidae), symbionts of the stony coral Stylophorapistillata (Scleractinia), ZooKeys 791, pp. 71-95 : 82-84

Spaniomolgus stylophorus sp. n. Figs 8, 9 b–d

Type locality.

Saudi Arabian Red Sea, reef near Thuwal, 22°12'04.30"N, 38°57'31.40"E.

Material examined.

1 ♀ holotype (ZMMU Me-1211) and 1 ♀ paratype (ZMMU Me-1212) from Stylophora pistillata (KAUST SA2013-12) collected at 1 m depth in the inner part of the reef; 1 additional ♀ from Stylophora pistillata (morphotype S. danae ) (KAUST SA2013-31) collected at 28 m depth in the outer part of reef (22°20'23.45"N, 38°50'52.33"E).

Etymology.

The specific epithet stylophorus refers to the host name Stylophora .

Description.

Adult female.

Body cyclopiform, with oval cephalothorax and cylindrical urosome (Figs 8a, 9b). Mean body length 1.15 mm (with range of 1.1 - 1.2 mm) and mean maximum width 365 µm (with range of 320 - 410 µm), based on two specimens. Somite bearing Sixth leg 1 completely separated from cephalosome. Epimeral areas of metasomal somites slightly angular. Fourth pedigerous somite smaller than preceding ones, its epimeral areas not visible in dorsal view.

Urosome 5-segmented, comprising fifth pedigerous somite, genital double-somite and three free abdominal somites (Fig. 8b). In dorsal view, only the postgenital somites visible. Leg 5-bearing somite slightly wider than long. Genital double-somite (Fig. 8b) bell-shaped; 170 µm minimum width (anterior half), 220 µm maximum width (posterior half) and 155 µm long; shorter dorsally than ventrally. Paired genital apertures bipartite, each comprising ventrolateral copulatory pore and dorsolateral gonopore (oviduct opening). Each genital area with two minute spiniform setae (Fig. 8b). Egg sac unknown. Three postgenital somites 120 × 180, 120 × 130 and 94 × 110 μm from anterior to posterior.

Caudal rami (Fig. 8b) elongated, 200 × 45 µm, 4.4 times as long as wide. With six setae, all relatively short and naked. Outer lateral seta 40 µm, outermost terminal seta 40 µm, innermost terminal seta 30 µm. Two median terminal setae broadened, 50 µm (outer) and 60 µm (inner) in length. Dorsal seta 25 µm.

Rostral area with hyaline setules (Fig. 9c, d).

Antennule, mandible, maxillule, maxilla and armature formula for legs 1-4 as for Spaniomolgus globus sp. n.

Antenna (Fig. 8c) 3-segmented; first segment 80µm long with small terminal hyaline seta; second segment 115 µm long with a seta medially; third segment 78 µm long with three hyaline setae medially, and two apical hyaline setae, with small recurved terminal claw 30 µm long. Length ratio of second to third segments (measured along inner margin) 1.5:1.

Maxilliped (Fig. 8d) 3-segmented; first segment unarmed; second segment robust, with two naked inner setae; third segment claw-like, with two setae medially equal in length; apex with pore.

Leg 4 (Fig. 8e) with 3-segmented exopod and 2-segmented endopod. Inner coxal seta and outer basal seta short and naked. Endopod reaching beyond middle of third exopodal segment, with two apical spines unequal in length, outer 38 µm and inner 70 µm, the latter spines with hyaline and serrated margins. Outer spines of exopod with smooth lamellae.

Leg 5 (Fig. 8b) with protopod incorporated into somite; outer basal seta naked. Free segment long, slender and recurved, 5.0 times as long as wide, bearing two apical setae unequal in length, inner most more than twice the length of outer one.

Male unknown.