The reproductive system of the female Ethusa mascarone was studied with a combination of histological and MRI-techniques. The study reveals a completely new type of eubrachyuran seminal receptacle. This receptacle consists of two largely separate chambers that engage with each other in a manner similar to shaking hands. One chamber facing the medial axis is lined by cuticle while the second chamber consists of a thick holocrine epithelium. Both chambers are connected by two openings of a unique structure. First, the glandular chamber opens ventro-laterally to the cuticle chamber via a laterally flattened connective duct that is lined by a highly folded cuticle. A second opening connects both chambers dorsally with the oviduct orifice. A distinct character is the cuticular hook-like projection that is situated in between the connection of oviduct opening, the glandular chamber and the cuticle chamber of the seminal receptacle. The complete seminal receptacle exhibits a combination of plesiomorphic and apomorphic characters. The arrangement of the receptacles featured in two separate chambers, including the ventro-lateral connection of the glandular chamber to the cuticle chamber, presumably reflects an early evolutionary stage of an eubrachyuran receptacle. In contrast, the dorso-lateral opening between both chambers, including the hook-like projection, appears to be an apomorphic character of at least E. mascarone. J. Morphol. 277:1497-1508, 2016. © 2016 Wiley Periodicals, Inc.
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Arthropod Struct Dev
January 2025
Zoological Museum, University of Kiel, Hegewischstrasse 3, 24105, Kiel, Germany.
The objective of this study is to gain a better understanding of the not well understood egg-transportation mechanisms through the female reproductive systems of crabs. For this, Carcinus maenas was chosen as a model to study the cuticular epithelium underlying the cuticle of the vagina and the ventral seminal receptacle. This cuticular epithelium is investigated by performing histochemical and ultrastructural analyses of the epithelial cells.
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View Article and Find Full Text PDFZootaxa
March 2024
Colección de Aracnológica (CARCIB); Programa Académico de Planeación Ambiental y Conservación (PLAYCO); Centro de Investigaciones Biológicas del Noroeste (CIBNOR) S.C. Km. 1 Carretera a San Juan de La Costa "EL COMITAN"; C.P. 23205; La Paz; Baja California Sur; Mexico.
In modern systematics, different sources of evidence are commonly used for the discovery, identification, and delimitation of species, especially when morphology fails to delineate between species or in underestimated species complexes or cryptic species. In this study, morphological data and two DNA barcoding markers-cytochrome c oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2)-were used to delimit species in the spider genus Loxosceles from North America. The molecular species delimitation analyses were carried out using three different methods under the corrected p-distance Neighbor-Joining (NJ) criteria: 1) Assemble Species by Automatic Partitioning (ASAP), 2) General Mixed Yule Coalescent model (GMYC), and 3) Bayesian Poisson Tree Processes (bPTP).
View Article and Find Full Text PDFNat Ecol Evol
November 2024
Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, USA.
Our understanding of animal ornaments and the mating preferences driving their exaggeration is limited by knowledge of their genetics. Post-copulatory sexual selection is credited with the rapid evolution of female sperm-storage organ morphology and corresponding sperm quality traits across diverse taxa. In Drosophila, the mechanisms by which longer flagella convey an advantage in the competition among sperm for limited storage space in the female, and by which female sperm-storage organ morphology biases fertilization in favour of longer sperm have been resolved.
View Article and Find Full Text PDFArthropod Struct Dev
May 2024
Department of Life Sciences, University of Siena, Siena, Italy. Electronic address:
The ultrastructural study on the female reproductive system of the beetle M. brevicauda (Mordellidae) confirmed the positive correlation between the length of the sperm and the size of the female seminal receptacle (Spermatheca). The spermatheca of the species is characterized by an apical bulb-like structure where the spermathecal duct forms numerous folds filled with sperm.
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