Spermatogenesis and Spermatozoa in Stygocapitella subterranea (Annelida, Parergodrilidae), an Enigmatic Supralittoral Polychaete

  title={Spermatogenesis and Spermatozoa in Stygocapitella subterranea (Annelida, Parergodrilidae), an Enigmatic Supralittoral Polychaete},
  author={G{\"u}nter Purschke and Mary C. Fursman},
The intertidal polychaete species Stygocapitella subterranea (Parergodrilidae) is characterised by extraordinary biology and morphology, resembling those of clitellates and Hrabeiella periglandulata, a terrestrial species of Annelida. An ultrastructural study of the spermatogenesis and spermatozoa was undertaken to elucidate whether these similarities might exhibit adaptive characters typical of annelids with highly derived reproductive modes. A second goal was to find out whether there are… 

Male genital organs in the eulittoral meiofaunal polychaete Stygocapitella subterranea (Annelida, Parergodrilidae): ultrastructure, functional and phylogenetic significance

The observations confirm that consistencies with either clitellates or H. periglandulata are the result of convergent evolutionary events and the relationship of Parergodrilidae to an orbiniid/questid clade receives support from the present data.

Ultrastructural investigation and in vitro recapitulation of spermatid differentiation in a potential bio-indicator species – The marine invertebrate Galeolaria gemineoa (Polychaeta: Serpulidae)

The concept that spermatid differentiation in this species is dependent on intrinsic developmental programming and does not require input from accompanying nurse cells is supported.

Phylogeny of basal descendants of cocoon-forming annelids (Clitellata)

Worms with ring-like clitella surrounding the body almost completely are herein renamed Euclitellata, and Oligochaeta is established as a valid clade for the hermaphroditic annelids bearing few or no chaetae.

Detailed analysis of the male reproductive system in a potential bio-indicator species – The marine invertebrate Galeolaria caespitosa (Polychaeta: Serpulidae)

The independence of spermatogenic cells from supporting cells in G. caespitosa raised the possibility of inducing spermiogenesis in vitro, which would provide a useful tool to dissect the mechanisms underlying this complex cell differentiation process in invertebrates and other higher order animals.

Ultrastructure developments during spermiogenesis in Polydora ciliata (Annelida: Spionidae), a parasite of mollusca

The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed and the formation of proacrosomal granules within the Golgi apparatus was discussed.



Male genital organs, spermatogenesis and spermatozoa in the enigmatic terrestrial polychaete Parergodrilus heideri (Annelida, Parergodrilidae)

The specific characters observed in P. heideri are typical of species with direct transfer of sperm and internal fertilisation; there are no synapomorphies with either the Clitellata or H. periglandulata; the similarities between these terrestrial Annelida are very likely due to a corresponding reproductive biology in similar habitats and thus do not reflect a common ancestor.

Vergleichende Ultrastrukturuntersuchungen der Eu- und Paraspermien von 13Protodrilus-Arten (Polychaeta, Annelida) und ihre taxonomische und phylogenetische Bedeutung

The morphology of the slender, filiform spermatozoa of 13Protodrilus species of 22 different populations is investigated by light and transmission electron microscopy and elucidates possible plesiomorphous and apomorphous sperm traits.

Ultrastructure of the spermatozoa of Parenterodrilus taenioides (Protodrilida: “Polychaeta”) and its phylogenetic significance

An ultrastructural study revealed that the similar structure of sperm suggests that sperm transfer and fertilization are very probably the same in P. taenioides as in Protodrilus.

Spermiogenesis and seminal receptacles in Aeolosoma singulare (Annelida, Polychaeta, Aeolosomatidae)

Spermatogenesis, spermatozoa, seminal receptacles and the transformations of sperm after mating were examined for the first time in the polychaete annelid Aeolosoma singulare from Lake Baikal and revealed a progressive reduction of the cytoplasmic droplet.

Spermiogenesis and Modified Sperm Morphology in the “Seepworm” Methanoaricia dendrobranchiata (Polychaeta: Orbiniidae) From a Methane Seep Environment in the Gulf of Mexico: Implications for Fertilization Biology

It is hypothesize that the unusual spermatozoon morphology in this species has evolved due to the hypoxic environment in which the adults live and that fertilization biology is likely modified in some way to minimize sperm exposure to high levels of hydrogen sulfide.

Spermatogenesis and sperm ultrastructure in the interstitial syllid Petitia amphophthalma (Annelida, Polychaeta)

The mature spermatozoa accumulate in the dorsal region of a seminal vesicle that extends over several segments and form a cytophore after the second maturation division, which leads to spermatogenesis in both primary and secondary sperMatocytes.

Sperm ultrastructure and spermatogenesis in the interstitial polychaete Sphaerosyllis hermaphrodita (Syllidae: Exogoninae)

The mature spermatozoa of Sphaerosyllis hermaphrodita (Polychaeta: Syllidae) were reconstructed from electron micrographs, identifying them as belonging to the modified sperm type often found in interstitial polychaetes.