Paraxial organ of a scorpion: structural and ultrastructural studies of Euscorpius tergestinus paraxial organ (Scorpiones, Euscorpiidae)

  title={Paraxial organ of a scorpion: structural and ultrastructural studies of Euscorpius tergestinus paraxial organ (Scorpiones, Euscorpiidae)},
  author={Nicol{\'e} Lauti{\'e} and Lydia Soranzo and Marie-Claire Lajarille and Roland Stockmann},
  journal={Invertebrate Reproduction \& Development},
  pages={77 - 90}
Summary By combining ultrastructural and histochemical approaches, the paraxial organs of Euscorpius tergestinus (syn. E. carpathicus; Scorpiones, Euscorpiidae) have been studied for the first time. The paraxial organs are symmetrical structures in the male genital system. They are located on each side of the mesosoma and end at the genital aperture. The paraxial organs have a glandular function. They are directly involved in the secretion of the two hemispermatophores, which are deposited in… 

The ultrastructure of book lung development in the bark scorpion Centruroides gracilis (Scorpiones: Buthidae)

There are differences and similarities in the formation of book lung and book gill lamellae and the homology hypothesis for these respiratory organs is supported or not supported depending on which developmental features are emphasized.

Ultrastructure of book gill development in embryos and first instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura)

The developmental observations herein and in an earlier study of scorpion book lungs show that the lamellae in book gills and book lungs result from some similar activities and features of the precursor epithelial cells: proliferation, migration, alignment and apical/basal polarity with secretion of cuticle from the apical surface and the basal surface in contact with hemolymph.

Testes Mass, but Not Sperm Length, Increases with Higher Levels of Polyandry in an Ancient Sex Model

As predicted by the sperm competition theory and according to what happens in other arthropods, testes mass increased in species with higher levels of sperm competition, and influenced positively spermatophore volume, but data was not conclusive for sperm length.

Successive matings produce opposite patterns on ejaculate volume and spermatozoa number in an ancient arthropod model with indirect sperm transfer

The production of spermatophore and ejaculate is energetically expensive for males. High mating rates may accelerate sperm depletion and progressively decrease the size of the ejaculates. Sperm



A study of a scorpion cuticle: I. The structure and staining reactions of the fully formed cuticle of Buthus quinquestriatus (H. & E.)

It is suggested that in spite of certain points of similarity with the cuticle of insects, the scorpion cuticle resembles that of spiders more closely than has been hitherto recognized.

The Male Genital System of the Scorpions, Buthus quinquestriatus

New methods have been adopted to resolve the structure of the ejaculatory organ and its supporting shaft of the scorpion, and several basal processes have been found, namely, the oblique vertical, longitudinal, superior, and inferior outer and inner processes.

Morphology and function of male genitalia (spermatophores) in Euscorpius italicus (Euscorpiidae, Scorpiones): Complex spermatophore structures enable safe sperm transfer

It is concluded that “safeguarding of sperm transfer” is one driving force for evolution of male genital complexity in scorpions, but also sexual selection by cryptic female choice could partly play a role.

An Examination of the Cuticles of two Scorpions, Pandinus imperator and Scorpiops hardwickii

The statement by Krishnan that chitin is present in the epicuticle is critically examined and a possible explanation of the differences which have been reported between the cuticles of different scorpions is offered.

Studies of male sexual tubes in hermit crabs (crustacea, decapoda, anomura, paguroidea). I. Morphology of the sexual tube in Micropagurus acantholepis (Stimpson, 1858), with comments on function and evolution

This is the first in‐depth study of a sexual tube in the Paguroidea, a group where a remarkable number of genera with species having these intriguing sexual structures are known.


It is postulated that the Chaerilidae are more closely related to scorpions with lamellifor m sperMatophores than they are to buthids, and their spermatophores are probably of a lamellIfor m "type" .

The jumping mechanism of Xenopsylla cheopis. I. Exoskeletal structures and musculature.

  • M. RothschildJ. Schlein
  • Biology
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1975
The jumping apparatus of the flea, which includes highly modified direct and indirect flight muscles, is described: attention is drawn to the various specializations of the exoskeleton which stiffen