Montacutella echinophila
| Montacutella echinophila | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Montacutella | ||||||||||||
| Jespersen , Lützen & Nielsen , 2004 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Montacutella echinophila | ||||||||||||
| Jespersen , Lützen & Nielsen , 2004 |
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Montacutella echinophila is a mussel species from the lentil mussel family(Montacutidae). The species is a commensal of the sea urchin Brissus latecarinatus . It is the type species and only species of the genus Montacutella Jespersen, Lützen & Nielsen, 2004. The species name is derived from Greek echinos = sea urchin and philos = loving.
features
The same-folding, almost triangular, inflated case is up to 7.9 millimeters long with a case height of 5.6 millimeters. The moderately prominent, broadly rounded vertebrae stand clearly in front of the middle of the length of the case. The dorsal edge slopes down moderately on both sides of the vertebra. The right valve has a protruding, almost vertical, blunt main tooth just below the vertebra that fits into a pit in the left valve. In the left valve there is a slightly smaller, triangular main tooth slightly in front of the vertebra. The internal ligament is strong and very long (up to 800 µm in large specimens) and sits in an almost horizontal pit behind the vertebrae.
The surface of the case has a matt glossy finish with numerous, irregular, growth stripes parallel to the edge and microscopic, radial stripes. The Prodissoconch II is 265 µm in size.
The soft body is almost colorless. In a specimen examined alive, the casing edges, the inflow and outflow siphons extended over the edge of the housing. However, they can be completely withdrawn into the housing. The middle area of the mantle is covered with numerous small papillae. The rear outflow opening is very small, while the combined opening for the foot and the inflow siphon is very large. The latter opening has curled edges and extends over the lower two thirds of the front and over the larger part of the ventral side. Only in the rear part of the ventral side (below the outflow opening) is the jacket fused over a shorter distance. The foot is wedge-shaped. The gills consist only of the inner half-leaf. The descending and ascending lamellae are connected to one another by some cross bridges. Mouth flaps (labial palps) are present. The opposing surfaces of the labial palps have numerous transverse ridges.
The species is probably segregated, as the five larger specimens examined were all females with ovaries and no male gonads . One specimen contained oocytes with a diameter of 20 to 25 µm. The other females carried embryos in the upper gill cavity in different stages of development (max. 50 to 55 µm in diameter). In addition, all females had semen bags (receptacula semines) with (foreign) sperm. The seed pouches consist of two egg-shaped pouches that extend from the intestinal sac to the rearmost part of the upper gill cavity. They are 400 to 500 µm long with a thickness of 250 µm. The opening is facing forward. They are fused together along the center line.
Similar genera or species
The simple toothing of the lock is similar to the genus Tellimya Brown, 1827 and also Neaeromya Gabb, 1872. In the latter genus, however, the left flap is toothless. In no other genus of the Montacutidae are right and left seed recipes fused in the middle. In Kurtiella bidentata , the unpaired, transversely oriented seed pouch has openings on the right and left side.
Geographical distribution and habitat
The species is so far only known from the type locality, a reef in front of the Phuket Marine Biological Center, Phuket , Thailand ( ).
The animals live with byssus threads attached to the anal spines of the irregular sea urchin Brissus latecarinatus , which is 3.5 to 8.0 centimeters long. The sea urchins live in coarse, clean sand between coral stocks from just below the low water line to a few meters water depth.
This species is not only host to Montacutella echinophila , but also to Scintillona brissae Morton & Scott, 1989 (family Galeommatidae ) and Brachiomya stigmatica Jespersen, Lützen & Nielsen, 2004 (family Montacutidae).
Taxonomy
The species and genus was first described in 2004 by Åse Jespersen , Jørgen Lützen and Claus Nielsen . Species and genus are listed as valid taxa by the MolluscaBase.
supporting documents
literature
- Åse Jespersen, Jørgen Lützen, Claus Nielsen: On three species and two new genera (Montacutella and Brachiomya) of galeommatoid bivalves from the irregular Sea Urchin Brissus latecarinatus with emphasis on their reproduction. Zoologischer Anzeiger, 243: 3-19, 2004 doi : 10.1016 / j.jcz.2004.04.001