• Publications
  • Influence
Fine structure of egg envelopes in some viviparous goodeid fishes, with comments on the relation of envelope thinness to viviparity
TLDR
The egg envelope of the full-grown oocytes before fertilization was examined by electron microscope in eight viviparous species of Goodeidae (Cyprinodontiformes) from the Mexican plateau and displayed short external processes resembling attaching filaments, which are known to be in many eggs.
The 18S rDNA sequences support polyphyly of the Hypsibiidae (Eutardigrada)
TLDR
The findings suggest polyphyly of the Hypsibiidae, and thus multiple evolutions of some structures currently applied as diagnostic characters (e.g., claws, buccal apophyses) within the Eutardigrada.
Comments on the eyes of tardigrades.
  • H. Greven
  • Biology, Medicine
    Arthropod structure & development
  • 1 December 2007
TLDR
Because of the scarcity of information on the tardigrade eyes, their homology with the visual organs of other bilaterians is currently difficult to establish and further comparative studies are needed.
Parental investment by skin feeding in a caecilian amphibian
TLDR
A remarkable form of parental care and mechanism of parent–offspring nutrient transfer in a caecilian amphibian is reported and provides a plausible intermediate stage in the evolution of viviparity in caecilians.
Parotoid macroglands in toad (Rhinella jimi): their structure and functioning in passive defence.
TLDR
It is suggested that the mechanism for venom discharge within all bufonids is possibly similar to that described herein for Rhinella jimi and that parotoids should be considered as cutaneous organs separate from the rest of the skin specially evolved for an efficient passive defence.
Mechanical properties of the skin of Xenopus laevis (Anura, Amphibia)
TLDR
The skin of X. laevis, although heterogeneous in structure, possesses features similar to those found in tissues with aligned collagen fibers such as tendons or fish skin, however, in anurans, the skin seems to play a more passive mechanical role during locomotion than in fish.
Survey of the oviduct of salamandrids with special reference to the viviparous species.
  • H. Greven
  • Biology, Medicine
    The Journal of experimental zoology
  • 1 November 1998
TLDR
Certain basic alterations in the uterine epithelium during pregnancy are most likely under endocrine control, and the development of the trophic zone, may be induced by interactions with the offspring.
Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation
TLDR
The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship.
Maternal Adaptations to Reproductive Modes in Amphibians
TLDR
This chapter surveys structural, physiological, and endocrinological adaptations as well as parental–offspring interactions in amphibians practicing oviductal, skin, vocal sac, and stomach incubation.
...
1
2
3
4
5
...