Classification of Amia Calva | Bowfin
- Phylum :- Chordata (Dorsal tubular nerve cord, notochord and gill-slits present.)
- Group :- Craniata (Cranium with brain present.)
- Sub phylum :- Vertebrata (Vertebral column present.)
- Division :- Gnathostomata (Jaws and paired appendages present.)
- Super Class :- Pisces (Paired fins, gills and skin with scales.)
- Class :- Osteichthyes (Bony fishes. Skin contains dermal scales. Paired lateral fins present. Gills, air bladder present. Cleavage meroblastic.)
- Sub-Class :- Actinopterygii (Modern fishes. Vertebrae amphicoelous. Caudal fin homocercal, Scales cycloid or ctenoid. Nostrils do not communicate with mouth cavity.
- Order :- Amiiformes (Tail heterocercal and overlapping cycloid scales.)
- Family :- Amiidae
- Genus :- Amia
- Species :- calva
Geographical distribution
- Amia calva is abundantly distributed in rivers and lakes of Central and Southern America. Upper Jurassic and Lower Tertiary.
Habit and habitat
- Amia calva is a fresh-water and carnivorous fish, feeding voraciously upon other fishes, insects and crustaceans.
General Characteristics of Amia Calva | Bowfin
- Commonly known as Bowfin, measuring about 60 cm in length.
- Shape of body is fusiform, compressed and divided into head, trunk and tail.
- Body covered by uniformly thin, overlapping and nearly cycloid scales.
- Head contains ventral mouth and dorsal eyes. The terminal mouth has a thick upper lip and a pair of dorsal barbels.
- Middorsal fin has long base and continuous for the greater part of the trunk and tail and contains about 48 rays. All fins short and devoid of fulcra.
- Paired fins are pectoral and pelvic.
- Anal fin near fan-shaped caudal fin. Air bladder often used as lung.
- Fish can breath atmospheric air and comes to the surface to engulf air into air bladder.
- Pyloric caeca absent. Tail is homocercal, lateral line distinct.
- Sexually dimorphic. Males are smaller than females (45 cm) and provided with a rounded black spot at the base of caudal fin.
- Two peculiar comb-like structures are found on the head. Male builds a nest in water weeds and guards the young until they can move themselves
Amia calva, commonly known as the bowfin, is a primitive freshwater fish native to North America. It is the sole surviving member of the family Amiidae, an ancient lineage that dates back over 150 million years. Bowfin are typically found in slow-moving waters such as swamps, backwaters, and rivers, where they are well-adapted to low-oxygen environments due to their ability to breathe air using their swim bladder.
Ecological Importance
- Predator Role:
- Bowfin are opportunistic predators that feed on a variety of prey, including fish, amphibians, crustaceans, and insects. They help regulate prey populations, contributing to ecological balance.
- Biodiversity Support:
- By preying on invasive species or overabundant prey, bowfin can indirectly support the health of native species and aquatic ecosystems.
- Habitat Adaptation:
- Bowfin thrive in low-oxygen and degraded environments, making them resilient species that contribute to the stability of these ecosystems.
- Nutrient Cycling:
- As both predator and prey, bowfin contribute to nutrient cycling by feeding on a variety of organisms and serving as prey for larger predators such as alligators and birds.
Conservation Status of Acipenser
- Status:
- Amia calva is listed as a species of Least Concern by the IUCN. It has a wide range and stable population across much of its native range in North America.
- Threats:
- Habitat Loss: While not critically endangered, bowfin populations may be affected by habitat destruction, such as wetland drainage and pollution.
- Misunderstanding and Overfishing: Bowfin are sometimes considered “trash fish” by anglers and are targeted or culled unnecessarily, despite their ecological role.
- Conservation Efforts:
- Maintaining the health of wetland and river habitats ensures the continued survival of bowfin populations.
- Raising awareness about their ecological importance can reduce unnecessary killing or culling by anglers.
Special features
Amia calva is the only one living species. Amia shows combination of primitive and advanced characters. The primitive characters include
- Dorsal, cellular and bilobed lung (air bladder),
- Spiral valve vestigial,
- Large jugal plate, well-developed branchiostegal rays, and non-pyloric caeca.
- The advanced characters include
- thin cycloid scales without ganoin
- fulcra absent in fin
- tail homocercal
- vertebrae solid and amphicoelous. This fish also shows parental care.
Identification
- Since this fish has continuous dorsal fin, anti above features, hence it is Amia.
