Cave rock from 4 5 mya dating technique internet dating business

Cyprinion may have entered the Middle East during the colonization event that isolated the genera Barbus sensu lato and Schizothorax in the European and Asian basins respectively.

The divergence of these species is similar in time to the radiation of the Leuciscinae supposedly centred in Siberia based on fossil records. (sic) from the Lower Miocene of Saudi Arabia showing an early date for the entry of cyprinids to the Afro-Arabian Plate.

Collares-Pereira (1994) argues that the polyploid condition (e.g. There are 2-4 unbranched rays (including rudimentary ones) in the dorsal and anal fins followed by the more numerous branched rays (the last two branched rays are counted as one).

The first pectoral and the first pelvic fin ray are unbranched and not included in counts.

Pharyngeal teeth lie on a modified, fifth gill arch which can be seen or probed behind the shoulder girdle, just inside the gill opening.

The arch has to be removed with dissecting equipment to count the teeth.

Tubercles are also used to fight other males and defend and clean nests. Nest building males are larger than females, the reverse of the situation in most fishes where egg-bearing females are the largest.

Not all species build nests and some simply broadcast eggs over weed, gravel or sand. This is a prolonged spawning season which ensures no single batch of eggs is lost to unfavourable, temporary environmental changes such as floods.

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Other common names in English for species include barbels, breams, roaches, snow trouts, bitterlings, shiners, daces, chubs, barbs, "sharks", among many others.

A horny pad on the underside of the basioccipital bone of the skull is used to masticate the food against.

Tooth form varies with the food - molar-shaped teeth are used to crush molluscs, flat but grooved surfaces for grinding plant food and sharp edged teeth for slicing various invertebrate foods.

Siberia was probably an important dispersion centre for both Leucicinae and Cyprininae at that time. Some species may enter brackish water but the family is primarily a freshwater one.

Carps have extremely sensitive hearing via the Weberian apparatus and this is thought to account for their success. This chemical stimulates other carps to flee and hide, another useful adaptation.


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