*** Welcome to piglix ***

Triops longicaudatus

Triops longicaudatus
Temporal range: Triassic–Recent
Triops-longicaudatus-dorsal-ventral-edit2.jpg
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Branchiopoda
Order: Notostraca
Family: Triopsidae
Genus: Triops
Species: T. longicaudatus
Binomial name
Triops longicaudatus
(LeConte, 1846)
Triopsrange.PNG
The range of Triops longicaudatus
Synonyms

Apus longicaudatus LeConte, 1846


Apus longicaudatus LeConte, 1846

Triops longicaudatus (commonly called longtail tadpole shrimp, American tadpole shrimp, or rice tadpole shrimp) is a freshwater crustacean of the order Notostraca, resembling a miniature horseshoe crab. It is characterized by an elongated, segmented body, a flattened shield-like brownish carapace covering two thirds of the thorax, and two long filaments on the abdomen. Triops refers to its three eyes, and longicaudatus refers to the elongated tail structures. Triops longicaudatus is found in freshwater ponds and pools, often in places where few higher forms of life can exist. Like its relative Triops cancriformis, the longtail tadpole shrimp is considered a living fossil because its basic prehistoric morphology has changed little in the last 70 million years, exactly matching their ancient fossils. Triops longicaudatus is one of the oldest animal species still in existence.

Triops longicaudatus is a member of the crustacean class Branchiopoda, which primarily contains freshwater animals with gills on their legs. The class Branchiopoda is divided into the subclasses Sarsostraca, containing fairy shrimp, and Phyllopoda, containing all other members (cladocerans, clam shrimps, and the tadpole shrimp). The subclass name, literally meaning leaf-footed, is derived from their flat, leaflike appendages. Notostracans are placed in the infraclass Calamanostraca, which also contains the extinct Kazacharthra.

Triops longicaudatus is usually greyish yellow or brown in color, and differs from many other species by the absence of the second maxilla. Apart from Triops cancriformis, it is the only tadpole shrimp species whose individuals display as many as three reproductive strategies: bisexual, unisexual (parthenogenetic), and hermaphroditic; see below. Triops cancriformis is easily recognizable by its yellow carapace with dark spots, whilst T. longicaudatus individuals have a uniform carapace. The species also appeared about 50 million years later, and, as its name suggests, its elongated tail structures (cercopods) are often nearly as long as the rest of the body; including the cercopods, the body may reach 75 mm (3.0 in) in length.


...
Wikipedia

...