Scyllarus subarctus Crosnier 1970
Creators: name: Genis-Armero, Rebeca
name: Guerao, Guillem
name: Abelló, Pere
name: González-Gordillo, J. Ignacio
name: Cuesta, José A.
name: Corbari, Laure
name: Clark, Paul F.
name: Capaccioni-Azzati, Romana
name: Palero, Ferran
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Scyllaridae
Scyllarus
Scyllarus subarctus

description: Scyllarus subarctus Crosnier, 1970
Phyllosoma, stage VII (PHMF 13, PHMF 51)
Dimensions. N = 7; TL = 9.1–10.9 mm; CL = 6.4–7.7 mm; CW = 7.4–8.7 mm; PDL = 1.1–1.4 mm. Cephalic shield (Fig. 2 A). Sub-rectangular; 1.2 × wider than long.
Antennule (Fig. 5 A). Peduncle 3-segmented, last segment shorter and carrying two flagella (primary and accessory); accessory flagellum longer than primary, unsegmented with 2 setae in external side and 1–3 longer setae in the apical region; primary flagellum unsegmented with 8–9 rows of sensory setae (aesthetascs). Antenna (Fig. 5 A). Biramous and unsegmented; longer than antennule.
Mandibles (Fig. 5 D, G). Asymmetrical dentition. Left mandible (Fig. 5 D) larger and with more teeth on incisor process than right (Fig. 5 G). Right mandible teeth are curved towards molar process while teeth of left mandible are elongated. Both mandibles with abundant small teeth distributed over surface and molar process crowned with many denticles.
Maxillule (Fig. 5 J). Uniramous. Coxal and basial endites with 7 setae (2 and 3 strong setae, respectively). Palp (endopod) absent.
Maxilla (Fig. 6 A). Endites, endopod and exopod (scaphognathite) not differentiated.
First maxilliped (Fig. 6 A). Unsegmented and cone-shaped; rudimentary bud.
Second maxilliped (Fig. 6 D). Five-segmented, with 0,1,2,10,3 setae respectively.
Third maxilliped (Fig. 4, 6 H, G). Five-segmented, with ventral coxal spine; distal part of propodus and dactyl densely setose. Two serrated and curved setae in distal end of propodus.
Pereiopods (Fig. 2 A–E; 6L). P1–4 biramous with ventral coxal spine and 5-segmented endopod; basis-ischiomerus (fused) with abundant spines scattered over the surface. Two large distal spines on ischio-merus and carpus; with long and strong spines on distal end of propodus, increasing in length from P1 to P4. Exopods with 22–26, 21–24, 18–22, 14–18 annulations respectively, each annulation carrying two long setae. Dorsal side of P1–3 covered with many spines, fewer on P4. P5 rudimentary and 2-segmented; exopod absent.
Pleon (Fig. 6 L). Undeveloped and unsegmented; with 4 pairs of rudimentary pleopods. Biramous uropods undeveloped. Telson with 2 long processes and 4 setae on posterior margin (one pair on dorsal and one pair on ventral sides).
Phyllosoma, subfinal stage (PHMF 56, PHMF 48, SNECII-E89_02)
Dimensions. N = 3; TL = 19.4–20.3 mm; CL = 12.6–13.1 mm; CW = 15.3–16.2 mm; PDL = 4.1–5.4 mm.
Cephalic shield (Fig. 3 A). Subrectangular, 1.2 × wider than long.
Antennule (Fig. 5 B). Accessory flagellum slightly longer than primary. Primary flagellum with 13–14 rows of aesthetascs.
Antenna (Fig. 5 B). Widening inner ramus. Same length as antennule.
Mandibles (Fig. 5 E, H). Similar to stage VII but with more teeth on both mandibles.
Maxillule (Fig. 5 K). Uniramous. Coxal endite with 12 setae (2 long and strong, and 10 small setae) and basial endite with 13 setae (3 long and strong, and 10 small setae).
Maxilla (Fig. 6 B). Endite and endopod poorly differentiated. Scaphognathite (exopod) rectangular shaped and with small anterior and posterior expansions. Lateral process of endite with trapezoidal shaped.
First maxilliped (Fig. 6 B). Rudimentary and slightly bilobed.
Second maxilliped (Fig. 6 B). 5-segmented with 0,1,3,13,3 setae respectively. Spines of fourth segment form a crown around the base of dactyl.
Third maxilliped (Fig. 6 I, J). More spines than previous stage.
Pereiopods (Fig. 3 A–E; 6M). P1–4 with more spines than stage VII; exopods with 32–34, 27–34, 30–32, and 23–30 annulations respectively. P5 without exopod, 3–segmented and reaching base of uropods; coxa with ventral spine and 2 spines on ischio-merus.
Pleon (Fig. 6 M). Four pairs of bilobed pleopods longer and narrower than stage VII; bilobed uropods; margin of telson is concave; elongated processes of telson shorter with respect to telson length. Two rows of 14–15 setae on ventral and dorsal side of telson.
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Phyllosoma, final stage (PHMF 92)
Dimensions. N = 8; TL= 27.0– 35.1 mm; CL = 15.5–20.7 mm; CW = 19.6–25.9 mm; PDL = 7.0– 10.2 mm.
Cephalic shield (Fig. 4 A). Subrectangular, 1.3 × wider than long.
Antennule (Fig. 5 C). Accessory flagellum unsegmented; primary flagellum shorter than accessory, unsegmented, with 16–17 rows of sensory setae.
Antenna (Fig. 5 C). Longer than antennule.
Mandibles (Fig. 5 F, I). Similar to stage VII, but internal row of teeth approaches the external row so that both rows meet.
Maxillule (Fig. 5 L). Coxal and basial endite with 11 and 10 setae respectively. Palp (endopod) absent.
Maxilla (Fig. 6 C). Endite and endopod poorly differentiated with 3 setae on superior margin of lateral process of endite. Scaphognathite (exopod) without setae, flattened and anterior and posterior parts considerably expanded.
First maxilliped (Fig. 6 C). Unsegmented and bilobed; outer lobe flattened and round; inner lobe conic-shaped and shorter.
Second maxilliped (Fig. 6 F). 5-segmented with 0,1,3,15,4 setae respectively; exopod bud present.
Third maxilliped (Fig. 6 K). Densely setose.
Pereiopods (Fig. 4 A–G; 6N). Exopods of P1–4 with 32–38, 27–38, 32–35 and 29–33 annulations respectively. One spine-like seta present at the distal end of the proximal segment of exopod. P5 reaching uropods, 5-segmented with ventral coxal spine, 2 distal spines on ischio-merus, carpus and propodus.
Gills (Fig. 4 F). Gill buds present: mxp3 and P1 with 1 pleurobranch, 1 arthrobranch and 2 podobranchs; P2–4 with 2 pleurobranchs, 1 arthrobranch, 2 podobranchs; P5 with 1 pleurobranch.
Pleon (Fig. 6 N, O). Pleopods biramous. Posterior margin of telson rounded with two postero-lateral processes. Two rows of 17–22 setae on dorsal and ventral sides of telson.
description: Published as part of Genis-Armero, Rebeca, Guerao, Guillem, Abelló, Pere, González-Gordillo, J. Ignacio, Cuesta, José A., Corbari, Laure, Clark, Paul F., Capaccioni-Azzati, Romana & Palero, Ferran, 2017, Possible amphi-Atlantic dispersal of Scyllarus lobsters (Crustacea: Scyllaridae): molecular and larval evidence, pp. 325-338 in Zootaxa 4306 (3) on pages 327-335, DOI: 10.11646/zootaxa.4306.3.2, http://zenodo.org/record/844752