The gill-breathing animals are those that have specialized organs called gills or gills that allow them to carry out the respiratory process in the aqueous medium in which they live.
These animals include fish, some reptiles early in their lives, most mollusks, crustaceans (although some have tracheal respiration), and some annelids and zoophytes..
Gills vary in structure from animal to animal. They range from simple filamentous epithelial structures to complex structures comprising hundreds of lamellae enclosed in a gill cavity or chamber..
They have multiple blood vessels and are continuously permeated by water flows, which makes gas exchange between water and blood possible..
Like other amphibians, the frog exhibits gill respiration early in its life cycle.
The gills allow it to breathe in water during its period as a larva and tadpole. When reaching adulthood, the gills disappear, then it begins to have a cutaneous and pulmonary respiration.
The octopus is a cephalopod mollusk that has gill respiration. The octopus has three hearts. Two of the hearts are housed near the base of the gills and they are in charge of directing the blood towards the gills where the gas exchange takes place..
Carbon dioxide is released and oxygen is obtained. The third heart is responsible for pumping oxygen-rich blood to all tissues of the animal.
The clam has two pairs of gills, which are very delicate structures formed by ciliated sheets that allow gas exchange in an efficient way..
A particular characteristic in these animals is that the gills also fulfill functions of osmotic regulation, excretion and digestion..
The respiratory system of the shark is made up of the gills or gills of cartilaginous tissue from which gill filaments are detached. These open and close to allow the passage of water and carry out the gas exchange.
Manta rays like sharks have a cartilaginous gill structure. This is located in the lower part of the body, near the base of its dorsal fins..
This marine snail, characteristic for the beauty of its shell, lives in the kelp forests of the reefs. The gill is located in the cavity of the mantle in front of the heart.
It is a mollusk that can measure up to 20 cm. His body is elongated and muscular and folds emerge from him that completely embroider it..
Young specimens are carmine red in color and as they age they turn brownish green with small spots. The gills are located on the right side of the head.
Carp is a freshwater fish native to Asia, but it is currently scattered throughout most of the world. Like other fish, its respiration is gill.
It is a freshwater fish with a flattened body and a triangular shape. It is characteristic for the size of its dorsal and anal fins that accentuate its triangular shape. As in the case of all fish, their respiration is gill.
It is a fish that belongs to the group of lungfish. These are fish that have lungs, in addition to their gills and that under certain environmental conditions can survive outside the water by breathing the oxygen found in the air..
The body of the Australian lungfish is elongated, its head is small and flattened and the end of its tail is pointed..
This fish, like the Australian lungfish, has the ability to survive long periods out of water thanks to its double breathing system: gill and lung..
It is a fish with a long, muscular body and a small, pointed head. It survives the dry months by burying itself in the mud, where it remains wrapped in a layer of mucus that it secretes..
It is another fish belonging to the group of lungfish typical of South America. Of the group of lungfish, it is the fish that presents greater dependence on air oxygen than on aqueous oxygen. Only 2% of its oxygen requirement is obtained through its gills.
In the dry stages, the lepidosiren digs a cave in the mud in which it buries itself and which it covers with a plug of mud with holes that allow it to take oxygen from the surface. Its body is elongated and thick similar to that of eels.
13- Sardines
14- Shrimp
15- Whale shark
16- Catfish
17- Seahorse
18- Toads
19- Axolotl
20- Prawns
21- Lobster
22- Tuna
23- Salamanders
24- Chunerpeton
25- Mixino
26- Lampreys
27- Sawfish
28- Electric Stripe
29- Yeti Crab
30- Coquina
31- Turbot
32- Sepia
33- Clown fish
34- Coquina
35- Silverside
36- Marine worm
37- Newt larvae
38- Golden
39- Marine polychaete
40- spider fish
41- Dule water snail
42- Ciprea tiger
43- Vampire Squid
44- Slugs
45- Aquatic mealybug
These are simple, primitive structures that develop as hollow outgrowths from the body wall. In echinoderms, these types of gills vary in appearance.
In some species such as starfish they appear as papilliform structures, while in sea urchins they are gill-shaped. In these animals, the gills work together with the tubular structures (tracheae) to carry out the respiratory function of gas exchange..
In annelids the respiratory process is usually carried out through the skin. However, some have additional gills. In some polychaetes there are highly vascularized gills attached to the notopodium.
In the arenicola, a burrowing polychaete, and ozobranchus, a leech, the gills or gills are branched tufts arranged segmentally and in pairs along the body. The tentacles of the sabellidae and snakeskin are also considered gill-like respiratory structures..
Among vertebrates, gills are present in frog larvae (tadpoles) or as a neotenic characteristic of some adult salamanders (axolotl, Necturus). Some fish also have external gills during the larval stage (elasmobranchs, lungfish).
Protopteran and lepidosiren larvae have four pairs of external gills early in their lives which are replaced by internal gills when the operculum develops..
Obviously the external gills have disadvantages. They can become obstacles during locomotion and are a source of attraction for predators.
For this reason, in most gill-breathing animals, the gills are located in partially closed chambers that provide protection for these delicate structures..
One of the main advantages of internal gills is that they allow the continuous flow of running water to ventilate the gill chambers. In addition, this arrangement of the gills allows the animal's body to be more streamlined..
In bivalves, tunicates, and some echinoderms, ciliary activity is responsible for the circulation of water through the branchial chamber. The animals receive their oxygen requirements and also their food supplies from the circulating water..
In crustaceans, several types of well-developed internal gill structures are observed. In these animals, the gills are made of vascularized laminar structures.
In the case of gastropod molluscs, the gills are located within the cavity of the mantle which receives continuous water currents.
Aquatic vertebrates have developed very efficient gill respiration. The gills are located in a chamber known as the opercular chamber. The oral cavity sucks water which is forced back through the gills to exit through the opercular cavity.
This flow of water over the respiratory epithelium is continuous and the respiratory current is produced by muscular movements which pump the water. This occurs thanks to a double pump mechanism that operates simultaneously..
On the one hand, the oral cavity functions as a pressure pump that forces water through the gills, while on the other, the opercular suction pump moves water through them..
The oral cavity and the opercular opening are protected by valves that remain static, but that move according to the degree of pressure exerted on them..
In many aquatic animals, especially fish, an important characteristic is that the flow of water through the gills is in only one direction and the flow of blood in the opposite direction. This is called the countercurrent principle and ensures a constant degree of oxygen tension between the water and the blood..
Yet No Comments