Fish Biology (Introduction, History, Importance, Classification, & More!)


Introduction to the Fish Biology

Aquatic fish are among the earliest known vertebrates in the world and evolved during the Devonian period, approximately 400 million years ago. They form a highly successful group of animals that live in all seas, rivers, lakes, canals, dams, dirty water, brackish water, estuaries and all places where there is water. They very from each other in shape, size and habits, ranging from less than 2cm to up to 18 meters. And the very wide distribution of fishes in a variety of habitats has resulted in many adaptations to their morphology, physiology and behavior. 

Fish Biology

History Of Fish Biology :- Father of Fish Biology Peter Artedi (1705-1735) and "In the history of fisheries management, few names shine more brightly than Fedor I. Baranov (1880–1942), the Russian mastermind who devised the groundbreaking 'catch equation.' This simple formula was a result of his dual expertise in mathematics and biology. Evidence continues to guide sustainable fishing practices by modeling the delicate dance between fish populations, catch, and fishing effort..

Importance of Fish in Ecology and Human Life:-

Fish play an important role in maintaining ecological balance within aquatic ecosystems. They help control populations of other species while ensuring a healthy and diverse environment. and fishes constitute a very important group of animals and provide a rich source of food, liver oil and many other by-products, such as fish meal, fish manure, isin glass, and Economically, fishes function in all branches such as ecological balance, Biodiversity, Nutrient cycling, Food web dynamics, Oxygen production, Industries contribute, Aquaculture,  High quality protein resource,  

Definition and Characteristics of Fish:-

Fish are a diverse group of  vertebrate animals that live in the fresh and salt waters of the world. They are characterized by the following 

Aquatic Vertebrates:- Fish are aquatic vertebrates with gills and libs in the shape of fins..

Respiration:- They breath through organs called gills.

Body Temperature:- Unlike mammals, fish are mostly cold-blooded or ectothermic, which means their body temperature changes along with the temperature of their surroundings.

Scales:- Body is usually covered with scales, but some are naked without any exo-skeleton.

Fins:- Fish have fins which are used for balance, steering, and propelling in the water.

Species:- There are approximately 34000 species of fish found in the world.

Evolution:- Fish have been on this planet for a very long time, dating back to about 450million years. 


 Classification of Fish

Various scheme of classification have been suggested by taxonomists in the past. Earlier authors generally based their classification on the morphological characters of living species. Later, as knowledge advanced, both living and fossil forms were taken into consideration and cladistic principles were applied. Among later authors, Berg(1940) and Romer(1959) have given detailed classification of fishes, which have generally been accepted. Bertin and Arambourg(1958), Greenwood et al.(1966) have suggested some significant modifications in the scheme. More recently, Lauder and Liem (1983), Nelson(1984) and Pough et al. (1989), have suggested a new scheme, which is often referred to as the modern classification of fishes.
Berg(1940) based his scheme of Classification on the works of C.Tate Regan and E,A. Stensio, S as to include both recent and fossil forms. He included all the Gnathostomes having gills as respiratory organs and fins for locomotion in the series Pisces and has divided then into the following seven Classes:
【PLACODERMS】
Class:
⟹ Acanthodii
⟹ Coccostei (arthrodira)
⟹ Pterichthyes(antiarchi)
SERIES PISCES
Elasmobranchii
Holocephali
Dipnoi
⟹ Teleostomi

Romer(1959) suggested a different classification and  combined Elasmobranchii and Holocephali into one class Osteichthyes (Dipnoi and Teleostomi of Berg). Several authors considered inclusion of Crossopterygii (lobe fins) in teleostomi by Berg, as an error. Romer therefore, divided bony fishes (Osteichthyes) into two sub-classes:

           (A) Sarcopterygii(Crossopterygii and Dipnoi) to include fishes with lobate paired fins.

           (B)  Actinopterygii, to include all the bony fishes without lobate fins.


Types of Fish

Thus according to Romer(1959) the series Pisces is divided into five classes, instead of seven, as shown below:

Classification of fishes
Classification of fish

Threats to Fish Populations

Fish is an aquatic organism. It has been living in water for millions of years. It is one of the living species even today, which is present in the whole world. There are many species of fish, out of which they have different populations. There are a total of 40,000 of them in the entire aquatic environment. .

Conclusion: Fish are remarkable aquatic inhabitants, the diversity that inhabits our planet's vast waters is astonishing, from ancient jawless lampreys and hagfish to smooth cartilaginous sharks, skates and rays, and abundant and diverse bony fishes. Etcetera. These aquatic wonders play a vital role in ecosystems; they contribute to food security, livelihoods and cultural heritage. It is the gateway to protecting our aquatic environment and ensuring sustainable fisheries.

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