The ultrastructure of spermatozoa of two species of Aegla (A. parana and A. quilombola) (Crustacea, Decapoda) endemic to Brazil.

The previously published ultrastructure of Aegla spermatozoa contributed to the phylogenetics of this unique taxon. The present study describes the spermatozoa of two additional aeglids, Aegla parana and A. quilombola.

Reappraisal of Hawaiian species of Corallianassa Manning, 1987 (Crustacea: Axiidea: Callichiridae).

Four species of the callichirid ghost shrimp genus Corallianassa Manning, 1987 are recognised in Hawaii based on evidence from morphology and the CO1 gene. Corallianassa borradailei (De Man, 1928) is a widespread Indo-West Pacific species now confirmed for Hawaii. Corallianassa lanceolata Edmondson, 1944 is an endemic species similar to C.

Ultrastructure of spermatozoa of spider crabs, family Mithracidae (Crustacea, Decapoda, Brachyura): Integrative analyses based on morphological and molecular data.

Recent studies based on morphological and molecular data provide a new perspective concerning taxonomic aspects of the brachyuran family Mithracidae. These studies proposed a series of nominal changes and indicated that the family is actually represented by a different number and representatives of genera than previously thought. Here, we provide a comparative description of the ultrastructure of spermatozoa and spermatophores of some species of Mithracidae in a phylogenetic context.

Male internal reproductive structures of European pea crabs (Crustacea, Decapoda, Brachyura, Pinnotheridae): vas deferens morphology and spermatozoal ultrastructure.

Pea crabs of the subfamily Pinnotherinae (Pinnotheridae) have a high investment in reproduction and an outstanding reproductive output, probably as an adaptation to the required increase in reproductive rate due to the pinnotherids small size and their parasitic, host-dependant way of life. In the present study, we investigate the male internal reproductive structures and the ultrastructure of spermatozoa of Pinnotheres pisum and Nepinnotheres pinnotheres by histological methods and both scanning- and transmission electron microscopy. In the Brachyura, the male internal reproductive systems generally consist of paired testes and corresponding vasa deferentia where spermatozoa develop and mature.

Spermatozoal ultrastructure in three Atlantic solenocerid shrimps (Decapoda, Dendrobranchiata).

The spermatozoal ultrastructure in three solenocerid shrimps (Solenocera membranacea, S. africana, and Pleoticus muelleri) from different Atlantic locations was examined with the aim of increasing understanding of the phylogenetic relationships in the Dendrobranchiata. A considerable structural similarity between the sperm of these species and those of penaeid shrimps supports a close affinity between the Penaeidae and Solenoceridae.

Spermatozoal ultrastructure in the spiny lobster Jasus novaehollandiae Holthuis, 1963 (Palinuridae, Palinura, Decapoda).

The spermatozoal ultrastructure of the spiny lobster Jasus novaehollandiae is most similar to that in other investigated palinurans and, in particular, to the spermatozoa of Panulirus species. Shared characters include the globular nucleus penetrated by the bases of three or more microtubular arms; an anteriorly situated cytoplasmic zone with mitochondria and conspicuous lamellar bodies; a complex, four-zoned acrosomal vesicle (however, lacking the crystalline region present in Panulirus) with a homogeneous region; a scroll region; a flocculent region; and a region of periacrosomal material that forms finger-like involutions into the flocculent region. The related scyllarid slipper lobsters (Scyllarus and Thenus) possess spermatozoa with acrosome morphology similar to that of Jasus, but the sperm is generally more flattened, numerous radiating acrosome fins are present, and the microtubular arms (in Scyllarus) are cytoplasmic in origin and not nuclear.