LEPIDOSTEUS (GARPIKE)

LEPIDOSTEUS (GARPIKE)

Contents hide
1) Classification of Lepidosteus (Garpike)
2) Geographical distribution
3) Habit and habitat
4) General Characteristics of Lepidosteus (Garpike)
5) Ecological Importance of Acipenser:
6) Conservation Status of Acipenser
7) Special features
8) Identification

Classification of Lepidosteus (Garpike)

  • 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 :- Lepidostiformes (Vertebrae solid, opisthocoelous and ganoid scales in oblique rows.)
  • Family :- Lepidosteidae
  • Genus :- Lepidosteus
Classification of Lepidosteus (Garpike)

Geographical distribution

  • Widely distributed in U.S.A. Upper Cretaceous to Recent.

Habit and habitat

  • Lepidosteus is found in fresh-water rivers. It is a voracious feeder on small fishes. Sometimes, it also comes out of the surface to emit bubbles of gases. The heavily armoured predaceous gars usually occur in shallow weedy areas.
Classification of Lepidosteus (Garpike)
Image Source IStock

General Characteristics of Lepidosteus (Garpike)

  • Commonly known as garpike, measures about 2 to 3 metres.
  • Body is elongated with short caudal region and is divided into head, trunk and tail.
  • Body is covered with thick rhombic ganoin-coated and articulated scales, about 50 to 65 along lateral line.
  • Scales articulate with one another by peg-and-socket joints.
  • Head is produced into snout.
  • Both the upper and lower jaws are elongated to form a sort of gar. Eyes are developed. Gills are covered by operculum.
  • Nostrils are found at the anterior end of beak.
  • Dorsal fin with few rays. Dorsal and anal fins are far back near the tail.
  • Caudal fin is rounded and semi-heterocercal. Paired pectoral and pelvic fins present.
  • Vertebrae opisthocoelous and solid with convex anterior and concave posterior ends, as in some reptiles and unlike other fishes. Vomer paired. Tail symmetrical, spiracles closed.
  • Air bladder is used as lung. It is vascularized and thus permits aerial respiration.

Lepidosteus, commonly known as gars, is a genus of ancient ray-finned fishes belonging to the family Lepisosteidae. These fish are native to North and Central America and are typically found in freshwater rivers, lakes, and brackish waters. Gars are known for their elongated bodies, armored scales, and long, toothy jaws. They are often referred to as “living fossils” because of their ancient lineage, which dates back over 150 million years

Ecological Importance of Acipenser:

  1. Predator Role:
    • Gars are ambush predators, feeding on smaller fish, crustaceans, and amphibians. They help regulate prey populations and maintain ecological balance in aquatic ecosystems.
  2. Prey for Larger Species:
    • Gars serve as prey for larger predators, including alligators and some bird species, contributing to the food web.
  3. Habitat Stability:
    • By occupying top or mid-level predator roles, gars help control invasive or overabundant species, indirectly supporting the health of native aquatic biodiversity.
  4. Indicator Species:
    • The presence of gars can indicate healthy aquatic systems as they thrive in environments with adequate food resources and good water quality.

Conservation Status of Acipenser

  • Status:
    • Most species of gars, including Lepisosteus osseus (longnose gar), are listed as Least Concern by the International Union for Conservation of Nature (IUCN). However, habitat degradation and human activities pose localized threats.
  • Threats:
    • Habitat Loss: Wetland drainage, dam construction, and river channelization disrupt gar habitats and spawning grounds.
    • Overfishing and Mismanagement: Gars are sometimes targeted by anglers as “trash fish,” leading to unnecessary killing or culling.
    • Pollution: Agricultural and industrial runoff can negatively impact gar populations by degrading water quality.
  • Conservation Efforts:
    • Protection of wetlands and river systems supports gar populations.
    • Educating the public on the ecological importance of gars can help reduce unwarranted culling.
Classification of Lepidosteus (Garpike)
Image Source : IStock

Special features

  1. Ancient Lineage:
    • Gars belong to an ancient group of ray-finned fishes, retaining many primitive features like ganoid scales and a simple vertebral column.
  2. Ganoid Scales:
    • Their hard, diamond-shaped ganoid scales are highly durable, providing excellent protection against predators and environmental hazards.
  3. Elongated Body and Jaws:
    • Gars are easily recognized by their long, cylindrical bodies and elongated jaws filled with sharp teeth, adapted for catching and holding slippery prey.
  4. Air Breathing:
    • Gars have a vascularized swim bladder that functions as a lung, allowing them to breathe air in low-oxygen environments.
  5. Survival in Harsh Conditions:
    • Gars are highly resilient and can survive in degraded or oxygen-poor waters where other fish cannot thrive.

Identification

  • Since this fish has toothed jaws, posterior dorsal fin and above features, hence it is Lepidosteus.

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