Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur GraphSearch.
Concept
Argulidae
Résumé
The family Argulidae, whose members are commonly known as carp lice or fish lice, are parasitic crustaceans in the class Ichthyostraca. It is the only family in the monotypic subclass Branchiura and the order Arguloida, although a second family, Dipteropeltidae, has been proposed. Although they are thought to be primitive forms, they have no fossil record.
List of Argulidae species
Branchiurans were once thought to be copepods but are now recognised as a separate subclass in the superclass Oligostraca due to their distinct morphological characteristics. There are approximately 170 species in four genera recognised in the family Branchiura. The centres of diversity are the Afrotropical and Neotropical realms.
Branchiurans have a flattened, oval body, which is almost entirely covered by a broad, oval carapace, four thoracic segments each with a pair of swimming legs, a pair of anterior compound eyes, and an unsegmented abdomen without appendages which ends in paired abdominal lobes separated by the medial anal cleft. They are compressed dorsoventrally and can be between two and vary in size from just a few millimetres to over long, with females usually somewhat larger than the males.
The mandibles are generally toothed hooks in Branchiurans. The maxillules provide sucking capability, and in the genera Argulus, Chonopeltis, and Dipteropeltis, the adults have a pair of suction cups that are from modified first maxillae. The genus Dolops, keeps the larval stages claw-like appendages into adulthood. It is still unknown whether the ancestral state of these organisms was to what suction discs or the hooked condition seen in Dolops, although it is thought that the specialized suctions discs are a later product of evolution. Also, females tend to be larger than the males. Between the genera there are multiple distinction between the sexes. For example, males in Argulus and Chonopeltis possess secondary sexual modifications on legs 2-4. The sexes both have their own sexual reproductive organs on their abdomens.
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.