''Placidochromis boops'' is a species of deep-water

African African or Africans may refer to: * Anything from or pertaining to the continent of Africa: ** People who are native to Africa, descendants of natives of Africa, or individuals who trace their ancestry to indigenous inhabitants of Africa *** Ethn ...

cichlid Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...

endemic to the southern portion of

Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest fre ...

. This species can reach a length of up to SL.

Etymology

The generic name of this species, ''Placidochromis'', is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word '' placidus'', meaning "of peaceful or tranquil appearance", and the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''chromis'', meaning "a fish", or possibly "a perch". The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''boops'', is derived from the Greek βόωψ ''boōps'', literally "cow-eye", referring to the large eyes of this species.

Morphology

Description

''Placidichromis boops'' has large eyes, and was named after this prominent feature. The dorsal profile of the head touches the upper margin of the eye, while the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

extends well beyond vertical at the anterior margin of the eye. The snout of this fish is long and pointed. The mouth is large, and its gape is inclined about 10° to the horizontal. The outer oral teeth are small and mainly

tricuspid The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle. The function of the valve is to allow blood to flow from the right atrium to the right vent ...

, however, some

bicuspid The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

teeth are present as well. The inner oral teeth are tricuspid, and the rows of inner teeth are close-set. The lower

pharyngeal jaw Pharyngeal jaws are a "second set" of jaws contained within an animal's throat, or pharynx, distinct from the primary or oral jaws. They are believed to have originated as modified gill arches, in much the same way as oral jaws. Originally hypo ...

contains a number of small, densely packed teeth, which are specialized for prey processing. Overall, it is a relatively large species, with the ventral body profile less convex than the dorsal body profile.

Coloration

''Placidichromis boops'' is

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, and coloration can be used as a simple means to sex mature males and females. Mature females and immature males have a brownish yellow body, six (6) vertical bars below the dorsal fin, a dark brownish snout, nape, and dorsum, pale brownish yellow fins, and grey spots on the soft dorsal. Meanwhile, mature males have a darker snout, a dark brown chin and belly, a faint grey band at the base of the dorsal fin, a white submarginal band and black tips, large dark spots which are occasionally merged into oblique bands on the soft dorsal, a darkly-colored anal fin, and darkly-edged caudal and ventral fins.

Meristics

''Placidochromis boops'' has 31 to 32 scales on the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

and 16 scales around the

caudal peduncle Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. There are 16 to 19

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 ...

on the lower limb of the first arch and 4 to 7 on the upper limb, making for a total of 22 to 26 gill rakers. It possesses a pair of

pectoral fins Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

and

pelvic fins Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

, one

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

, one

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

and one

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. The pectoral fins have no spines and 14 to 15 soft-rays, the dorsal fin has 14 to 15 spines and 10 to 11 soft-rays, and the anal fin has three (3) spines and 8 to 9 soft-rays.

Distribution and habitat

Placidochromis boops is

benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

, and has been observed in a depth range of . It lives exclusively within the freshwater

. This species has three recorded occurrences, all within the southern portion of

. It has been observed once in Senga Bay, north of the Nankumba Peninsula; and twice in the southwest arm of the lake, between Domwe Island, Senga Bay, and north of Mvunguti.

Reproduction

Little is known about ''Placidochromis boops'' reproduction. However, the

generation A generation refers to all of the people born and living at about the same time, regarded collectively. It can also be described as, "the average period, generally considered to be about 20–⁠30 years, during which children are born and gr ...

length is estimated to be about 1-2 years.

Relationship with humans

Conservation status

The

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

has assessed ''Placidochromis boops'' as a

least-concern species A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

, as no major, widespread threats to its survival have been identified. The entirety of its geographical distribution overlaps with

Lake Malawi National Park Lake Malawi National Park is a national park at the southern end of Lake Malawi in Malawi, Southeast Africa. It is the only national park in Malawi that was created with the purpose of protecting fish and aquatic habitats. Despite this being its m ...

, and it has never been collected by the

aquarium trade Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture. Origins of fishkeeping Fish have ...

References

{{Taxonbar, from=Q5563372 Placidochromis Cichlid fish of Africa Taxa named by Mark Hassens Fish described in 2004 Fish of Lake Malawi