Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here


No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this article

+ Tax (if applicable)
Add to Favorites
You must be logged in to use this functionality

image of Crustaceana

The branchiopod shrimp, Triops longicaudatus, inhabits ephemeral pools, and individuals must develop rapidly if breeding is to occur. Age-related differences in physiology, foraging behavior and predation pressures should make it more adaptive for young individuals to dwell near the surface, and the adults on the bottom. Consequently, young T. longicaudatus should be photopositive whereas older individuals should be photonegative. We tested light-dark preferences in the first five instars of lab-reared T. longicaudatus. Photonegativity increased with age, with instar 2 preferring lighted environments significantly more than instars 4 and 5. The first two instars were more active under dark conditions than under light conditions, suggesting an orthokinetic mechanism for habitat segregation. These changes may be correlated with the development of the compound eyes.

Le branchiopode Triops longicaudatus habite des mares éphémères, et les individus doivent se développer rapidement si la reproduction survient. Des différences liées à l’âge, relatives à la physiologie, au comportement de fouissage et aux pressions de prédation rendraient plus avantageux pour les jeunes de se tenir près de la surface et pour les adultes, sur le fond. En conséquence, les jeunes T. longicaudatus seraient photopositifs tandis que les individus plus âgés seraient photonégatifs. Nous avons testé les préférences lumière-obscurité chez les cinq premiers stades de T. longicaudatus élevés au laboratoire. La photonégativité augmentait avec l’âge, le stade 2 préférant significativement les environnements éclairés, plus que les stades 4 et 5. Les deux premiers stades étaient plus actifs dans des conditions d’obscurité que dans les conditions de lumière, suggérant un mécanisme orthocinétique pour la séparation de l’habitat. Ces changements peuvent être corrélés au développement des yeux composés.


Full text loading...


Data & Media loading...

Article metrics loading...



Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Subscribe to ToC alert
  • Get permissions
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
    Crustaceana — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation