Physoclisti

Last updated

Physoclisti are, collectively, fishes that lack a connection between the gas bladder and the alimentary canal, with the bladder serving only as a buoyancy organ.

Contents

Addition and removal of the gases from the gas bladder in such physoclistous fishes occurs through specialised structures called the gas gland and ovale respectively. The pneumatic duct that connects the gut and gas bladder is present in the embryos of these fish but it is lost during development. This anatomical state (the physoclistous condition) is believed to be evolutionarily derived from the ancestral physostomous state.

Some fishes, such as eels, are anatomically physostomous, but their gas bladders function similar to those of physoclists.

See also

Related Research Articles

<span class="mw-page-title-main">Anatomy</span> Study of the structure of organisms and their parts

Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine.

<span class="mw-page-title-main">Bladder</span> Organ in humans and vertebrates that collects and stores urine from the kidneys before disposal

The bladder is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra. The typical adult human bladder will hold between 300 and 500 ml before the urge to empty occurs, but can hold considerably more.

<span class="mw-page-title-main">Perch</span> Genus of fishes

Perch is a common name for fish of the genus Perca, freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Perciformes, from the Greek: πέρκη, simply meaning perch, and the Latin forma meaning shape. Many species of freshwater gamefish more or less resemble perch, but belong to different genera. In fact, the exclusively saltwater-dwelling red drum is often referred to as a red perch, though by definition perch are freshwater fish. Though many fish are referred to as perch as a common name, to be considered a true perch, the fish must be of the family Percidae.

The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body. The dual function of excretory systems is the elimination of the waste products of metabolism and to drain the body of used up and broken down components in a liquid and gaseous state. In humans and other amniotes most of these substances leave the body as urine and to some degree exhalation, mammals also expel them through sweating.

<span class="mw-page-title-main">Swim bladder</span> Gas-filled organ that contributes to the ability of a fish to control its buoyancy

The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish to control their buoyancy, and thus to stay at their current water depth without having to expend energy in swimming. Also, the dorsal position of the swim bladder means the center of mass is below the center of volume, allowing it to act as a stabilizing agent. Additionally, the swim bladder functions as a resonating chamber, to produce or receive sound.

<span class="mw-page-title-main">Fish anatomy</span> Study of the form or morphology of fishes

Fish anatomy is the study of the form or morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish.

<span class="mw-page-title-main">Euteleostomi</span> Clade including most vertebrates

Euteleostomi is a successful clade that includes more than 90% of the living species of vertebrates. Both its major subgroups are successful today: Actinopterygii includes most extant fish species, and Sarcopterygii includes the tetrapods.

The zàng-fǔ organs are functional entities stipulated by traditional Chinese medicine (TCM). They constitute the centrepiece of TCM's general concept of how the human body works. The term zàng (脏) refers to the organs considered to be yin in nature – Heart, Liver, Spleen, Lung, Kidney – while (腑) refers to the yang organs – Small Intestine, Large Intestine, Gall Bladder, Urinary Bladder, Stomach and Sānjiaō.

<span class="mw-page-title-main">Torso</span> Central part of the living body

The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals, from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a human — is usually divided into the thoracic segment, the abdominal segment, and the pelvic and perineal segments.

<i>Arapaima gigas</i> Species of fish

Arapaima gigas, also known as pirarucu or simply arapaima, is a species of arapaima native to the basin of the Amazon River. Once believed to be the sole species in the genus, it is among the largest freshwater fish. The species is an obligate air-breather, so needs to come to the surface regularly to gulp air.

As distinct from the Western medical concept of urinary bladder, this concept from traditional Chinese medicine is more a way of describing a set of interrelated functions than an anatomical organ.

<span class="mw-page-title-main">Weberian apparatus</span> Anatomical structure that connects the swim bladder to the auditory system in fishes

The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles. The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi. The structure itself consists of a set of minute bones that originate from the first few vertebrae to develop in an embryonic ostariophysan. These bones grow to physically connect the auditory system, specifically the inner ear, to the swim bladder. The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone.

Terminologia Anatomica is the international standard for human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology, a program of the International Federation of Associations of Anatomists (IFAA). The second edition was released in 2019 and approved and adopted by the IFAA General Assembly in 2020. Terminologia Anatomica supersedes the previous standard, Nomina Anatomica. It contains terminology for about 7500 human anatomical structures.

<span class="mw-page-title-main">Amphibious fish</span>

Amphibious fish are fish that are able to leave water for extended periods of time. About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of terrestrial locomotory modes, such as lateral undulation, tripod-like walking, and jumping. Many of these locomotory modes incorporate multiple combinations of pectoral-, pelvic-, and tail-fin movement.

<span class="mw-page-title-main">Sand grey mullet</span> Species of fish

The sand grey mullet is a species of mullet found in coastal marine waters of Australia.

<span class="mw-page-title-main">Loricarioidea</span> Superfamily of fishes

Loricarioidea is a superfamily of catfishes. It contains the six families Trichomycteridae, Nematogenyiidae, Callichthyidae, Scoloplacidae, Astroblepidae, and Loricariidae. Some schemes also include Amphiliidae. This superfamily, including Amphiliidae, includes about 156 genera and 1,187 species.

<span class="mw-page-title-main">Argentiniformes</span> Order of fishes

The Argentiniformes are an order of ray-finned fish whose distinctness was recognized only fairly recently. In former times, they were included in the Osmeriformes as suborder Argentinoidei. That term refers only to the suborder of marine smelts and barreleyes in the classification used here, with the slickheads and allies being the Alepocephaloidei. These suborders were treated as superfamilies Argentinoidea and Alepocephaloidea, respectively, when the present group was still included in the Osmeriformes.

<span class="mw-page-title-main">Swim bladder disease</span> Disease of fish

Swim bladder disease, also called swim bladder disorder or flipover, is a common ailment in aquarium fish. The swim bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming. A fish with swim bladder disorder can float nose down tail up, or can float to the top or sink to the bottom of the aquarium.

<span class="mw-page-title-main">Physostome</span>

Physostomes are fishes that have a pneumatic duct connecting the gas bladder to the alimentary canal. This allows the gas bladder to be filled or emptied via the mouth. This not only allows the fish to fill their bladder by gulping air, but also to rapidly ascend in the water without the bladder expanding to bursting point. In contrast, fish without any connection to their gas bladder are called physoclisti.

<span class="mw-page-title-main">Fish physiology</span> Scientific study of how the component parts of fish function together in the living fish

Fish physiology is the scientific study of how the component parts of fish function together in the living fish. It can be contrasted with fish anatomy, which is the study of the form or morphology of fishes. In practice, fish anatomy and physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the later dealing with how those components function together in the living fish. For this, at first we need to know about their intestinal morphology.

References