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The shovelnose sturgeon (Scaphirhynchus platorynchus) [5] is the smallest species of freshwater sturgeon native to North America. It is often called hackleback , sand sturgeon , or switchtail . Switchtail refers to the long filament found on the upper lobe of the caudal fin (often broken off as adults).
The Syr Darya sturgeon (Pseudoscaphirhynchus fedtschenkoi), or Syr Darya shovelnose sturgeon, [1] is a species of fish in the family Acipenseridae. It is found in Kazakhstan, Tajikistan and Uzbekistan, where it is endemic to the Syr Darya River and, before its drainage, the Aral Sea .
Pseudoscaphirhynchus kaufmanni (Kessler, 1877) (Amu Darya sturgeon) Historically, the two species in the Amu Darya River were known to hybridize . [ 11 ] Unusually, P. fedtschenkoi occurs (or occurred) in three morphs that can be separated by the length of their snout and tail filament, and P. kaufmanni occurs in two morphs that can be ...
The Amu Darya sturgeon feeds on small fish and aquatic insect larvae, with large individuals being mostly piscivorous. [1] [5]Studies in the 1960s and 1970s showed that Amu Darya sturgeon reach maturity when 5–8 years old (slightly later in females than males), but in the 1990s the youngest mature individuals only were 4 years old, possibly due to environmental changes in their habitat. [7]
Conservation efforts at the grass roots level are also instrumental in helping to preserve sturgeon populations, such as Sturgeon For Tomorrow [62] which was founded in 1977, consists of volunteers and a sturgeon guarding program to monitor known spawning sites. The organization has grown exponentially over the years and has become "the largest ...
The dwarf sturgeon, little shovelnose sturgeon, or small Amu-Darya shovelnose sturgeon (Pseudoscaphirhynchus hermanni) is a species of fish in the family Acipenseridae. It is found in Turkmenistan , Uzbekistan and probably in Tajikistan .
An estimate based on 30 protein-encoding nuclear markers suggest 204.1 million years ago, research on mitochondrial genomes suggest 155.2 million years ago, and Bayesian dating based on the combined matrix of molecular (mitogenomes) and morphological characters set the divergence to 162 (195–137) million years ago.
The guitarfish, also referred to as shovelnose rays, are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small, ray-like wings. The combined range of the various species is tropical, subtropical, and warm temperate waters worldwide.