''Synodontis schall'', the Wahrindi, is a species of

upside-down catfish The name upside-down catfish is most commonly used by aquarists to refer to the mochokid catfish '' Synodontis nigriventris'' alternately known to ichthyologists as the blotched upside-down catfish or false upside-down catfish. However, a number ...

widespread in northern

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

. This species is in the largest genus of the family

Mochokidae The Mochokidae are a family of catfishes (order Siluriformes) that are known as the squeakers or known as upside-down catfish (although not all species swim upside-down). There are nine genera and about 200 species of mochokids. All the mochokid ...

. This species grows to a length of TL.

Distribution

''Synodontis schall'' is a species of

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

found in

. It is found mainly in

Lake Nubia A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...

and is one of the only ''Synodontis'' species that have thrived in this lake and have adapted to new conditions, unlike the other species. Synodontis schall is able to adapt to many different kinds of food and habitats, increasing the chances of survival.

Appearance and anatomy

''Synodontis schall'' has a shield on its body and has strong bony

spine Spine or spinal may refer to: Science Biology * Spinal column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoology), ...

s on the

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectora ...

and

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

fins. Some areas of new

evolutionary Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certa ...

forces have allowed for the ''Synodontis schall'' to have different

phenotypes In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properti ...

. Recent studies have found evidence for an increase number of teeth and

gill rakers Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the ...

which could possibly point to a change from them being

herbivores A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

carnivores A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

. The

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

of ''Synodontis schall'' is whitish in appearance. Its walls are very thick and

elastic Elastic is a word often used to describe or identify certain types of elastomer, Elastic (notion), elastic used in garments or stretch fabric, stretchable fabrics. Elastic may also refer to: Alternative name * Rubber band, ring-shaped band of rub ...

, with the posterior section being thicker than the front one. The roof of the front section of the swim bladder is directly attached to the backbone and the muscles which are connected to it are able to compress and contract the swim bladder. The grunting sounds created by the swim bladder are most likely made by the

vibration Vibration () is a mechanical phenomenon whereby oscillations occur about an equilibrium point. Vibration may be deterministic if the oscillations can be characterised precisely (e.g. the periodic motion of a pendulum), or random if the os ...

of its walls. The sound is a deep grunting sound that can be heard for up to five meters away. The sound starts off sharply and then fades out within one fifth of a second. The fish will produce sounds when it is scared, in pain, when it has

aggressive Aggression is behavior aimed at opposing or attacking something or someone. Though often done with the intent to cause harm, some might channel it into creative and practical outlets. It may occur either reactively or without provocation. In h ...

behavior and attacks other fish, and when it's

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

Diet

The diet of ''Synodontis schall'' is one of

macrophytes Aquatic plants, also referred to as hydrophytes, are vascular plants and non-vascular plants that have adapted to live in aquatic environments ( saltwater or freshwater). In lakes, rivers and wetlands, aquatic vegetations provide cover for aquat ...

and

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, which are the two main types of food for them, fish and egg scales, insect

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

, and molluscs. This suggests that they are

omnivores An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

Reproduction

Not much is known about the

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: Asexual reproduction, asexual and Sexual ...

of ''Synodontis schall''. Physical and biological factors can affect the fish as it matures. July to October is the time for spawning for them and an increase in spawning activity occurs when there is a lot of rain.

Relationship to humans

''Synodontis schall'' are very important to

Benin Benin, officially the Republic of Benin, is a country in West Africa. It was formerly known as Dahomey. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north-west, and Niger to the north-east. The majority of its po ...

, a country in Africa. Fishermen in Africa catch these fish in their nets and so they must break the spines of the fish to get them out of their nets. ''Synodontis schall'' can be caught for food or even traded since they are prized fish.

References

External links

{{DEFAULTSORT:Synodontis Schall schall Catfish of Africa Freshwater fish of Kenya Freshwater fish of West Africa Fish of Cameroon Fish of Chad Fish of Egypt Fish of Ethiopia Fish of Sudan Fish described in 1801 Taxa named by Marcus Elieser Bloch Taxa named by Johann Gottlob Theaenus Schneider