COMPARATIVE SPERMATOZOAL ULTRASTRUCTURE OF THE 3 DROMIACEAN FAMILIES EXEMPLIFIED BY HOMOLODROMIA-KAI (HOMOLODROMIIDAE), SPHAERODROMIA-LAMELLATA (DROMIIDAE), AND DYNOMENE TANENSIS (DYNOMENIDAE) (PODOTREMATA, BRACHYURA)
D. Guinot et al., COMPARATIVE SPERMATOZOAL ULTRASTRUCTURE OF THE 3 DROMIACEAN FAMILIES EXEMPLIFIED BY HOMOLODROMIA-KAI (HOMOLODROMIIDAE), SPHAERODROMIA-LAMELLATA (DROMIIDAE), AND DYNOMENE TANENSIS (DYNOMENIDAE) (PODOTREMATA, BRACHYURA), Journal of crustacean biology, 18(1), 1998, pp. 78-94
The monophyletic Dromiacea, including Sphaerodromia lamellata, Homolod
romia kai, and Dynomene tanensis, here studied, have the following cha
racters: (1) operculum perforate, but lacking the thoracotreme apical
button; (2) opercular projections into the subopercular material, diag
nostic of homolids, absent: (3) operculum discontinuous with the capsu
le, unlike raninoids; (4) operculum moderately thick, not extremely th
in as in the cyclodorippoids Tymolus and Xeinostoma; (5) operculum not
extremely wide, contrasting with the great width in cyclodorippoids:
(6) periopercular rim and (7) accessory opercular ring absent, being v
ariably present in eubrachyurans; (8) subopercular protuberance throug
h operculum well developed (synapomorphy), weak in homolids; (9) true
acrosome ray zone absent; (10) peripheral border of outer acrosome zon
e herder not ragged, unlike some xanthoids: (II) anterolateral pale zo
ne of acrosome contents present (autapomorphy): (12) xanthid ring abse
nt; (13) subacrosomal chamber or perforatorium extending preequatorial
ly, unlike Ranina ranina: (14) head of perforatorium bilateral (autapo
morphy); (15) corrugations of the wall of the perforatorial chamber ab
sent; (16) centrioles apparently absent; (17) posterior median process
of the nucleus absent; (18) thickened ring (typical of Eubrachyura) a
bsent; (19) concentric lamellae (typical of Thoracotremata) in the out
er acrosome zone absent; (20) capsular chambers absent: and (21) capsu
lar flange absent. unlike Ranina ranina and Raninoides sp. Spermatolog
ically Sphaerodromia lamellata appears closer to the dynomenid Dynomen
e tanensis than it is to the mutually paraphyletic Dromidiopsis edward
si and Stimdromia lateralis. The spermatozoon of Homolodromia kai (Hom
olodromiidae) shares a striking putative synapomorphy with Paradynomen
e tuberculata: a Range-like lateral extension of the lower acrosome zo
ne; both species appear to lie within a dromiid clade. Neither the Dro
miidae nor the Dynomenidae appear monophyletic spermatologically. The
spermatozoal evidence is discussed in the light of a brief review of n
on-spermatozoal morphology. General morphology and spematozoal ultrast
ructure both strongly endorse monophyly of the Dromiacea.