Pourtalesia miranda
| Pourtalesia miranda | ||||||||||||
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Pourtalesia miranda |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Pourtalesia miranda | ||||||||||||
| A. Agassiz , 1869 |
Pourtalesia miranda is a species of the irregular sea urchin in the family Pourtalesiidae. It belongs to the benthos of the soft sediments in the deep sea and was found in the northern Atlantic at sea depths between 450 and 5850 m. In the East Atlantic, the species occurs from the Biscay to Iceland , in the West Atlantic it isnativefrom the Caribbean to the Davis Strait .
features
The Pourtalesiids are irregular sea urchins, so the animals give up their radial symmetry during ontogenesis and become bilaterally symmetrical and acquire an elongated shape that is untypical for sea urchins. The animals become 40 mm long. The anterior side appears truncated. The flanks run almost parallel to each other and converge posteriorly to form a more or less clearly differentiated subanalrostrum, which is bordered by a fasciole. The aboral side is slightly arched, the oral side kovex. The primary tubercles are arranged in short, more or less horizontally aligned rows.
The animals lack an Aristotle lantern , which is characteristic of most sea urchins.
ecology
The irregular deep sea forms are detritus eaters, for which the sea snow sedimenting from the upper water layers serves as a food basis. To do this, they absorb the sediment sludge and filter out the nutrients that they can use.
Individual evidence
- ↑ Schultz, Heinke AG: Handbook of Zoology. Echinoidea: with bilateral symmetry. Irregularia. Walter de Gruyter GmbH & Co KG, Berlin, ISBN 3-11-036853-6 , p. 131 .
- ^ A b WoRMS - World Register of Marine Species - Pourtalesia debilis Koehler, 1926. Retrieved on May 1, 2019 .