Caecoserolis Wägele, 1994: 10
Caecoserolis
Poore and Brandt 1997: 161
Myopiarolis
New genera and species of the marine isopod family Serolidae (Crustacea, Sphaeromatidea) from the southwestern Pacific
Bruce, Niel
ZooKeys
2009
2009-08-26
18
18
17
76
7NRG7
Wagele, 1994
Wagele
1994
[140,452,729,756]
Malacostraca
Serolidae
Caecoserolis
Animalia
Isopoda
53
70
Arthropoda
genus
Caecoserolis Wägele, 1994: 10(not Caecoserolisof Poore and Brandt 1997: 161; = Myopiarolis gen. n.)
Typespecies. Serolis brinki Kensley, 1978; original designation ( Wägele 1994).
Description. Headlateral lobe mesial margin with single concavity; anterolateral lobes forming of continuous margin with pereonite 1; anterior submarginal ‘ridge’ absent; posterior margin without ornamentation. Eyesabsent. Pereonitesall entire, articulating; pereonite 1 anterior margin not strongly bent dorsally, dorsally without tubercles. Coxaeof pereonites 2–4 articulated, with dorsal sutures; 2–4 and pereonite 6 entirely lacking coxal keys; distal margin truncate; coxae 6 wide, laterally or distally broad, extending proximal to insertion of uropod peduncle. Ventral coxal plates2–4 meeting midline; simple, smooth; plates 6 and 7 entirely separate. Pleonitesdistally narrow or acute, laterally overlapped by coxae 6, extending posteriorly along pleotelson. Sternites5–7 visible, fused. Sternalplates of pleonites 1–3 3-cornered, with acute median point, without median ridge. Pleotelsondorsal surface not vaulted, with weak median longitudinal carina, without paired sublateral carinae; pleotelson posterior margin evenly rounded, without distinct exit channel. Antennuleflagellum 1.2–2.0 as long as peduncle articles 3 and 4, extending to pereonite 2. Antennapeduncle articles 4 and 5 broad, article 5 less than 5 times as long as greatest width; flagellum three-quarters as long as peduncle article 5. Epistomeevenly rounded. Mandibleincisor with two posterior cusps; left mandible lacinia mobilis three-quarters as wide as incisor or larger, right lacinia mobilis distally multicuspid; mandibular spine distally serrate. Maxillipedpalp with 3 articles; article 3 cordiform, longer than wide. Pereopod 1carpus RS–state not known (pilose vsserrate); propodal palm setae all RS, alternating straight and flattened, wide RS finely pilose, narrow RS distally bifid, with simple flagellum. Pereopod2 propodus inferior margin without heel; palm straight; unguis simple, blunt. Penialopenings narrowly separated. Pleopods1–3 peduncles subquadrate. slightly narrower distally, pleopods 1–3 peduncles with coupling setae. Pleopod2 endopod lamellar part slightly shorter than ramus. UropodsBiramous, inserted on pleotelson mid-laterally, positioned laterally, not forming part of continuous body outline; less than one-third as long as pleotelson, endopod distally rounded.
Remarks. Caecoserolisbelongs with the group of genera characterised by having a distal stem on pleopod 2 endopod, approximating to the ‘Group B’ of Wägele (1994). The genus can be identified by the flat (or weakly domed) pleotelson that lacks lateral carinae, antenna with broad peduncular articles 4 and 5, pleopod peduncles that are sub-quadrate (slightly narrower distally than proximally) and by the short uropods inserted mid-laterally on the pleotelson; another less precise character is that Caecoserolishas a flatter body than related genera. All but the typespecies of Caecoserolishave been transferred to the Myopiarolis gen. n.Th e characters that most readily separate these two genera (in parentheses for Myopiarolis) include antenna peduncle articles 4 and 5 broad with article 5 less than 5 times as long as greatest width (slender, elongate, 4.6–6.3 and 8.6–10.3 as long as wide respectively), pleopods 1–3 peduncles quadrate or subquadrate (triangular), pereonite 1 anterior margin anterior margin weakly indented (distinctly indented), pereonites all with visible entire sutures (pereonites 5–7 sutures medially fused), simple and flat pleotelson that lacks sub-lateral carina (pleotelson vaulted, with sub-lateral carinae), coxae 6 not extending posteriorly to pleonites (extending posteriorly to pleonites) and penial openings narrowly separated (fused in all species of Myopiarolis).
Distribution.The genus is monotypic, with one western Indian Ocean species, off the Natal coast of South Africa.