Mussels in general are likely able to respond to chemical cues for spawning and other behaviors.
Perception Channels: tactile ; chemical
Quadrula metanevra is listed on several state threatened and endangered lists. Monkeyface mussles are endangered in Ohio, threatened in Wisconsin and Minnesota, and special concern in Arkansas. Due to decreasing water quality throughout its range this species may be becoming more rare.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Fertilized monkeyface eggs are kept in the female’s gills and develop into glochidia (larvae). The females may contain glochidia in the gills from May to July in Minnesota. They are released and must attach to host fish at the gills or fins. The glochidia live as a parasite until they develop into juveniles. After transformation, the juveniles detach and become free living at the bottom of the stream or river.
Development - Life Cycle: metamorphosis
No negative economic impacts are known for monkeyface mussels.
Mussels in general are good indicators of water quality. This is because they do not move around much, can be long living and can be analyzed for contaminants that are in the water where they live. As the quality of the water declines so may the population of the mussels. Mussels have also been important in the cultured pearl industry. Thicker shelled species are harvested to seed pearl oysters.
Positive Impacts: body parts are source of valuable material
Unionid mussels filter the water, provide substrate for aquatic insects and are a part of nutrient cycling in streams. Some of the known host fish for the glochidia of this species are the sunfish (Lepomis), sauger (Stizostedion canadens) and the bluegill (Lepomis macrohirus).
Ecosystem Impact: creates habitat; parasite
Species Used as Host:
Monkeyface mussels are primarily filter feeders on algae, bacteria, protozoans and other organic matter present in the water. Monkeyfaces draw water in through their incurrent siphon and the food and oxygen are removed from their gills. The filtered water and waste are released from an excurrent siphon.
Other Foods: detritus ; microbes
Foraging Behavior: filter-feeding
Primary Diet: herbivore (Algivore)
The monkeyface mussel, Quadrula metanevra, has a Nearctic distribution that encompasses the Mississippi River, Ohio River, and Tennessee River basins in the United States. Within Minnesota, this mussel used to reside in the Minnesota, the Mississippi and St. Croix Rivers. Monkeyface mussles are still found in the Mississippi river, but they are very rare within Minnesota waters. They are believed to have been extirpated from the Minnesota River.
Biogeographic Regions: nearctic (Native )
Monkeyface mussels may be found in medium to large rivers and streams. The monkeyface lives mostly in areas with mixed sand and gravel or gravel areas.
Average depth: 2 m.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: rivers and streams
The specific lifespan of the monkeyface is unknown. However, unionid mussels can be long-lived, with some mussel species living from decades to a century or more.
The outer shell color of monkeyfaces can be a green or light to dark brown. The shells will usually have zig-zags with a green line. Monkeyface mussels can have v-shaped markings as well, but these are more likely to be on the younger mussels. The shell is thick, round or square-like. The shells also have a posterior edge that has large knobs. The inner shell is white on one end while the other end has iridescent colorings. Monkeyface get their name from the profile of the posterior edge of the shell, where the outline looks like the silouette of a monkey's face.
Range length: 5.1 to 12.7 cm.
Average length: 8.9 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Unionid mussels in general are preyed upon by raccoons (Procyon lotor), muskrats (Ondotra zibethicus), and river otters (Lontra canadensis). Their hard shells and the muscles that hold them closed protect them from predators.
Known Predators:
Anti-predator Adaptations: cryptic
Monkeyfaces spawn once a year in the spring. Males release gametes into the water that are taken up by the females.
Mating System: polygynandrous (promiscuous)
Monkeyfaces are short-term brooders, meaning the females brood the larvae (glochidia) in their gills for only a few months in the summer. Reproduction starts with males releasing sperm directly into the water. The females downstream siphon the sperm into their gill chamber where the eggs are fertilized. The eggs mature in the gills to become glochidia. After being brooded for a few weeks or months, the glochidia are discharged into the water and will attach to a host fish. Brooding females were found in Tennessee between March and July. Glochidia drop from the host after they transform into juveniles.
Breeding interval: Monkeyface mussels breed once yearly.
Breeding season: Monkeyface mussels breed from May to July in Minnesota.
Key Reproductive Features: seasonal breeding ; fertilization (Internal ); ovoviviparous
After the eggs are fertilized, the larvae, called glochidia, reside in the female's gills for a few months until they are released into the water.
Parental Investment: pre-fertilization (Provisioning); pre-hatching/birth (Provisioning: Female, Protecting: Female)
Theliderma metanevra, common name the monkeyface, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
It is native to the eastern United States, where it lives in large to medium-sized rivers. Although it has been extirpated from certain sections of its range, it is still widespread and fairly common.[1]
Theliderma metanevra, common name the monkeyface, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
It is native to the eastern United States, where it lives in large to medium-sized rivers. Although it has been extirpated from certain sections of its range, it is still widespread and fairly common.
