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Vol. 50 No. 4, 2011
Spermatozoon Ultrastructure of Prisogaster niger (Wood, 1828) (Mollusca: Vetigastropoda): Supporting Affinities between the Prisogasterinae and Turbininae
Gonzalo A. Collado1,*, Claudio L. Correa1 , Marco A. Méndez1 , and Donald I. Brown2
1Laboratorio
de Genética y Evolución, Departamento de Ciencias Ecológicas, Facultad
de Ciencias, Univ. de Chile, Las Palmeras 3425, Santiago, Chile
2Laboratorio
de Biología de la Reproducción y del Desarrollo, Departamento de
Biología y Ciencias Ambientales, Facultad de Ciencias, Univ. de
Valparaíso, Gran Bretaña 1111, Valparaíso, Chile
Gonzalo A. Collado, Claudio L. Correa, Marco A. Méndez, and Donald I. Brown (2011) Recent
phylogenetic analyses of Vetigastropoda using DNA sequences suggest
that the subfamilies Prisogasterinae and Turbininae form a monophyletic
group within the recently redefined family Turbinidae. To verify this
systematic arrangement, we describe the spermatozoon ultrastructure of Prisogaster niger,
a reproductive anatomical component that has been successfully used in
phylogenetic investigations of vetigastropods, and compare the results
with previously published information from other trochoidean taxa based
on a phylogeny of the group. Prisogaster niger has a primitive
spermatozoon, or aquaspermatozoon, typical of invertebrates with
external fertilization. The sperm has a conical pointed acrosome which
is > 50% of the head length, a barrel-shaped nucleus, a midpiece
with 2 centrioles and 5 spherical mitochondria, and a simple flagellum
with 9+2 axonemes. Compared to other trochoideans, the spermatozoon of P. niger
is notably similar in structure to those of the Turbininae, with shared
synapomorphies (e.g., an elongated conical pointed acrosome and a broad
subacrosomal space) that suggest a close relationship between the
Prisogasterinae and this subfamily, and that Prisogaster may have originated from an ancestral Turbininae.
Key words: Gastropoda, Turbinidae, Prisogasterinae, Sperm, Morphology.
*Correspondence: E-mail:g.collado@eudoramail.com
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