Speaking of number of species de peces in the planet is to delve into one of the most fascinating and complex fields of biology. Fish, ancient inhabitants of rivers, lakes, seas, and oceans, form one of the most diverse groups in the animal kingdom. From the origins of aquatic life to the present day, these animals have undergone extraordinary evolution. Their presence is vital in aquatic ecosystems, and their study arouses both scientific curiosity and the admiration of nature enthusiasts and experts.
The question of how many species de peces The number of species currently in existence may seem difficult to determine. However, thanks to ongoing research and the development of advanced scientific techniques, experts have been able to estimate increasingly precise numbers. Furthermore, new species are discovered every year, reflecting the unexplored nature of many aquatic environments, especially the deep sea.
These fascinating animals not only give life and color to the ecosystems they inhabit, but also reveal a impressive genetic and adaptive diversityFish exist in almost every aquatic environment imaginable, from icy waters near the poles to hot springs, from mountain rivers to the abyssal depths of the oceans.
In this article we will explore the number of species de peces recognized, their main groups and classes, details about their biology, threats, ecological importance and everything that allows us to better understand the immensity and relevance of fish on our planet.
How many species de peces exist in the world?
Fish constitute the oldest and largest group of vertebrates of the Earth. According to the most up-to-date scientific data, the number of species de peces identified around 28.000This figure is approximate and is constantly growing due to new discoveries and taxonomic revisions being carried out around the world.
Scientists believe that fish represent approximately 9,6% of all known animal species, a figure that underscores its evolutionary and ecological significance. This impressive diversity is distributed across thousands of aquatic habitats around the globe, adapting to very different conditions and resources.
In addition, it is estimated that around 400 families de peces These groups group all of these species, distributing them into classes and subclasses based on morphological, genetic, and evolutionary criteria. Within this extensive repertoire, more than 8.000 species are of ornamental importance, as they are bred in aquariums and water gardens around the world.
It is important to note that, due to the vastness and depth of the oceans, a large percentage of species remain to be discovered. It is likely, according to experts, that there are thousands of species still unknown for science, especially those that live in deep or remote areas that humans have barely accessed.
The work of cataloging and studying fish corresponds mainly to the ichthyology, a branch of zoology dedicated to the study of fish. The constant classification and updating of species allows us not only to discover new life forms, but also to improve our understanding of biodiversity and ecological relationships in aquatic ecosystems.
Key concepts: What is a fish and what is a species?
To understand the magnitude of diversity de peces It is essential to first clarify what exactly is considered a fish and what the term species means in this context.
Un fish It is an aquatic vertebrate that breathes primarily through gills and moves using its fins. The body of fish is usually covered with scales, and most have simple blood circulation. Although there are exceptions, most fish lay eggs and reproduce outside the female's body.
Fish can inhabit both fresh and salt water, and have adapted to a huge variety of environments and temperatures. cold-blooded animals (ectotherms), which means their body temperature depends on the environment.
The term species, in biology, refers to the set of organisms capable of reproducing among themselves and generating fertile offspring. A species is characterized by having a common genetic pool and by presenting similar morphological traits. Therefore, when we talk about species de peces, we refer to natural groups of individuals who share a specific biological and genetic identity, differentiating themselves from other groups with which they cannot interbreed fertilely.
Delimiting species is not always straightforward, as genetic, morphological, and behavioral studies are often required to confirm that they are distinct groups. Advances in molecular genetics have made it possible to identify new species and better understand the evolutionary relationships between them.
Main groups and classification of species de peces
The enormous variety de peces The existing diversity has led scientists to classify them into large groups or classes. This classification is based on anatomical, physiological, and evolutionary characteristics, allowing species with common traits to be grouped together and facilitating their study.
- Jawless fish (Agnatha)They comprise the most primitive and least numerous groups, currently represented by lampreys and hagfish.
- Cartilaginous fishes (Chondrichthyes). Characterized by having a skeleton made of cartilage instead of bone. This group includes sharks, rays, and chimeras.
- Bony fishes (Osteichthyes)They constitute the largest and most diverse class. Their skeletons are made of bones, and they are further subdivided into ray-finned and lobe-finned fish.
These classes reflect different stages of fish evolution and demonstrate these animals' ability to adapt to a wide variety of habitats.
Jawless fish: Agnatha
The agnate They are the oldest and most primitive fish. Few species currently survive, belonging to two subgroups: lampreys and hagfish.
- lampreysThey have an elongated, gelatinous, cylindrical body, scaleless and extremely slippery. They superficially resemble eels, although they are not closely related. Lampreys live in fresh and salt water and reproduce by laying eggs. Most species are parasites of other fish, attaching to them to feed on their blood.
- hagfish or "hagfish": They are even stranger, with long bodies covered in a slimy substance. They lack jaws but have developed external structures that allow them to hold prey. Their main diet is carrion found on the deep seabed, where light is practically nonexistent. They have a toothed tongue that they can use to tear the flesh of other animals.
Both groups represent basal evolutionary branches of vertebrates and offer clues to the earliest steps in fish evolution.
Cartilaginous fish: sharks, rays and chimeras
The cartilaginous fish (Chondrichthyes) are characterized by having a skeleton composed of cartilage instead of bone. This group is also considered one of the oldest and most resilient in evolution.
- Tiburones - SharksFamous marine predators, sharks feature a streamlined body, powerful jaws, and extremely keen senses. Although they often have a fearsome reputation, many shark species are endangered due to overfishing and habitat destruction.
- StripesWith flattened bodies and wing-like pectoral fins, rays live close to the seabed. They are distinguished from sharks by the arrangement of their gills and their body shape.
- ChimerasNicknamed "ratfish," chimaeras are a small group of marine species that inhabit deep waters. Their morphology is reminiscent of both sharks and rays. They are especially interesting for the study of evolution because they retain very ancient characteristics.
Cartilaginous fish fulfill a fundamental ecological role as top predators and population regulators of other aquatic animals.
Bony fishes: the greatest diversity in the aquatic kingdom
Most species de peces They belong to the class of bony fish (Osteichthyes). This group represents the greatest diversity, with thousands of species adapted to all types of aquatic environments. Bony fish have a hard skeleton made of bones and usually have gills protected by an operculum.
- ActinopterygiansThese are fish whose fins have bony or cartilaginous rays. They make up the largest percentage of species and range from the popular clownfish to tuna, encompassing countless life forms and sizes.
- SarcopterygianThey are bony fish with lobe fins, a group that includes coelacanths and lungfish, and are largely considered living fossils. Sarcopterygians are especially important as the ancestors of the first terrestrial vertebrates (amphibians).
Bony fishes have colonized virtually every aquatic ecological niche on the planet and offer a wide variety of behaviors, shapes, and adaptations.
Ecology, feeding and adaptations of fish
The fish They have different types of diet, which allows them to occupy multiple ecological roles:
- Carnivores: They feed on other animals, whether smaller fish, invertebrates or specific prey.
- herbivorous: They mainly consume aquatic plants and algae.
- omnivores: Its diet is mixed, adapting to what is available in its environment.
- FiltersLike the whale shark, these fish filter the water to capture small organisms such as plankton.
The body shape, fin arrangement, and mouth type of each fish are the result of evolutionary adaptations to their habitat and available diet. Fish can be found in environments as diverse as coral reefs, high mountain rivers, deep lakes, polar waters, and even hot springs.
Regarding their distribution, fish are also classified according to the environment they occupy:
- Pelagic fishThey live far from the bottom, in open waters, like tuna or sardines.
- Benthic fish: They remain close to or in contact with the bottom, like sole or conger eels.
- Necto-benthic: They combine free-swimming habits with a certain dependence on the seabed.
Ecological importance and role of fish in ecosystems
Fish are not only one of the most important food sources for humans and numerous animals, but also maintain the health and balance of aquatic ecosystems. Their role is fundamental in food chains, controlling populations of organisms and facilitating nutrient recycling. More about its importance in ecosystems.
Furthermore, many fish participate in impressive migrations, such as salmon and eels. These migrations can cover thousands of kilometers and are essential not only for the reproduction and survival of species, but also for the biodiversity of the ecosystems they traverse.
Some species de pecesSome species, such as the whale shark and the large freshwater catfish, reach colossal sizes and live for more than a century. Others, however, are tiny and short-lived, reproducing in large numbers but living for only a few months.
Conservation and threats to species de peces
Despite their abundance and diversity, fish face serious threats Globally, hundreds of species are threatened with extinction or have disappeared completely due to human activities such as overfishing, habitat destruction, water pollution, the introduction of invasive species, and climate change.
The International Union for Conservation of Nature (IUCN) continually conducts risk assessments for thousands of species. de pecesHowever, many species still lack sufficient data to be properly catalogued and protected. Recent studies have shown that the percentage of vulnerable species is considerably higher than previously estimated.
The loss of species de peces It affects not only biodiversity but also human food security and the proper functioning of aquatic ecosystems. Models have been developed that use artificial intelligence to predict and detect extinction risks for understudied species, allowing for the anticipation of ecological crises and improved conservation management.
Some regions such as the Coral Triangle, the South China Sea and certain areas of the coasts of Australia and North America are considered biodiversity hotspots and require special attention for the conservation of their endemic species.
Interesting facts about the biology and behavior of fish
- CommunicationFish communicate using sounds, chemicals dissolved in the water, movements, and color changes. They may make buzzes, grunts, and other sounds for defense, reproduction, or territorial marking.
- SensesThey have highly developed senses. Many fish can perceive vibrations with their lateral line, detect electric fields, or distinguish colors and light signals even in low-light environments.
- Social behaviorThere are solitary species and other highly gregarious ones that form schools to protect themselves from predators and increase feeding efficiency.
- Reproduction: Most are oviparous, but there are also viviparous species or those with very complex reproductive methods, such as parental care or sex change throughout life.
Some fish, such as the clownfish, have developed unique mechanisms to identify members of their group using ultraviolet visual cues, demonstrating the sophistication of their sensory and social perception.
Today, sport fishing, aquariophilia and gastronomy continue to increase interest and knowledge about the diversity of species. de peces.
It is worth highlighting the importance of scientific studies and technological advances (such as molecular genetics and artificial intelligence) that allow us to discover new species and design more effective conservation strategies.
The journey of discovery about species de peces It's far from over. With each expedition and each technological advance, our knowledge and our responsibility to protect and value the extraordinary variety and beauty of fish grows. Caring for them means caring for life on Earth and the balance of the ecosystems that sustain us.
