Sylvain Le Bris, Frankreich
Info
Isognomon nucleus is a byssus-bound mussel of the genus Isognomon.
The shell of the mussel is small, oblique-uniform, fairly solid and not fragile, its outer surface is covered with coarse, converging lamellae and usually encrusted.
The inner surface is smooth and pearly, the ventral margin is the same color as the outer surface.
Its hinge area is strong and consists of numerous elongated teeth. The color is variable, ranging from brownish-purple to grayish-black.
There are various size specifications for the shell on the internet, ranging up to 14 cm.
We base our specification of 2.5 cm shell length on scientific reports.
Isognomon nucleus prefers to live in dense groups for several reasons:
By living together in large, dense colonies, the mussels protect each other from strong wave energy, drying out at low tide, dehydration, and overheating.
In the densely packed group, moisture is better retained, and the inner mussels in particular are better protected from extreme conditions.
A dense collection of many mussels makes it more difficult for predators to remove individual mussels, and the presence of many individuals can also reduce the risk for individual animals, similar to a school of fish that forms a bait ball.
Isognomon nucleus is a free-living organism; the mussels release their gametes into the water, where fertilization takes place externally.
In a large, closely knit group, the probability of egg cells and sperm meeting is much higher than if the animals were scattered throughout the sea.
These winged mussels use byssus threads to attach themselves to hard substrates such as rocks, roots, or mangroves.
Once a group has established itself over a longer period of time, additional mussels can attach themselves to the individuals already attached, creating a stable colony.
Group formation increases survival, facilitates reproduction, and improves attachment to suitable locations — a great example of an ecological and evolutionary group advantage.
Synonyms.
Isognomon acutirostris (Dunker, 1869) · unaccepted
Isognomon acutirostris Otuka, 1936 · unaccepted (junior subjective synonym)
Isognomon dentifer (Krauss, 1848) · unaccepted
Isognomon rupella (Dufo, 1840) · unaccepted
Melina dentifera (Krauss, 1848) · unaccepted
Parviperna francisensis (Cotton & Godfrey, 1938) · unaccepted > junior subjective synonym
Parviperna perexigua Iredale, 1939 · unaccepted (junior subjective synonym)
Parviperna rupella (Dufo, 1840) · unaccepted
Pedalion francisensis Cotton & Godfrey, 1938 · unaccepted > junior subjective synonym
Perna acutirostris Dunker, 1869 · unaccepted > nomen nudum
Perna dentifera Krauss, 1848 · unaccepted (junior synonym)
Perna lobata Reeve, 1858 · unaccepted (junior subjective synonym)
Perna nana A. Gould, 1850 · unaccepted (junior subjective synonym)
Perna nucleus Lamarck, 1819 · unaccepted (superseded combination)
Perna pectinata Reeve, 1858 · unaccepted (junior subjective synonym)
Perna planorbis Dufo, 1840 · unaccepted (junior subjective synonym)
Perna quadrangularis Reeve, 1858 · unaccepted (junior subjective synonym)
Perna rupella Dufo, 1840 · unaccepted (junior subjective synonym)
The shell of the mussel is small, oblique-uniform, fairly solid and not fragile, its outer surface is covered with coarse, converging lamellae and usually encrusted.
The inner surface is smooth and pearly, the ventral margin is the same color as the outer surface.
Its hinge area is strong and consists of numerous elongated teeth. The color is variable, ranging from brownish-purple to grayish-black.
There are various size specifications for the shell on the internet, ranging up to 14 cm.
We base our specification of 2.5 cm shell length on scientific reports.
Isognomon nucleus prefers to live in dense groups for several reasons:
By living together in large, dense colonies, the mussels protect each other from strong wave energy, drying out at low tide, dehydration, and overheating.
In the densely packed group, moisture is better retained, and the inner mussels in particular are better protected from extreme conditions.
A dense collection of many mussels makes it more difficult for predators to remove individual mussels, and the presence of many individuals can also reduce the risk for individual animals, similar to a school of fish that forms a bait ball.
Isognomon nucleus is a free-living organism; the mussels release their gametes into the water, where fertilization takes place externally.
In a large, closely knit group, the probability of egg cells and sperm meeting is much higher than if the animals were scattered throughout the sea.
These winged mussels use byssus threads to attach themselves to hard substrates such as rocks, roots, or mangroves.
Once a group has established itself over a longer period of time, additional mussels can attach themselves to the individuals already attached, creating a stable colony.
Group formation increases survival, facilitates reproduction, and improves attachment to suitable locations — a great example of an ecological and evolutionary group advantage.
Synonyms.
Isognomon acutirostris (Dunker, 1869) · unaccepted
Isognomon acutirostris Otuka, 1936 · unaccepted (junior subjective synonym)
Isognomon dentifer (Krauss, 1848) · unaccepted
Isognomon rupella (Dufo, 1840) · unaccepted
Melina dentifera (Krauss, 1848) · unaccepted
Parviperna francisensis (Cotton & Godfrey, 1938) · unaccepted > junior subjective synonym
Parviperna perexigua Iredale, 1939 · unaccepted (junior subjective synonym)
Parviperna rupella (Dufo, 1840) · unaccepted
Pedalion francisensis Cotton & Godfrey, 1938 · unaccepted > junior subjective synonym
Perna acutirostris Dunker, 1869 · unaccepted > nomen nudum
Perna dentifera Krauss, 1848 · unaccepted (junior synonym)
Perna lobata Reeve, 1858 · unaccepted (junior subjective synonym)
Perna nana A. Gould, 1850 · unaccepted (junior subjective synonym)
Perna nucleus Lamarck, 1819 · unaccepted (superseded combination)
Perna pectinata Reeve, 1858 · unaccepted (junior subjective synonym)
Perna planorbis Dufo, 1840 · unaccepted (junior subjective synonym)
Perna quadrangularis Reeve, 1858 · unaccepted (junior subjective synonym)
Perna rupella Dufo, 1840 · unaccepted (junior subjective synonym)
