| Denticetopsis | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Siluriformes |
| Family: | Cetopsidae |
| Subfamily: | Cetopsinae |
| Genus: | Denticetopsis Ferraris, 1996 |
| Type species | |
| Denticetopsis sauli Ferraris, 1996 | |
Denticetopsis is a genus of catfishes (order Siluriformes) of the family Cetopsidae.
Originally Denticetopsis as described by Ferraris in 1996 was restricted to two species, D. royeroi and D. sauli. These two species have proved to be a subunit of a larger clade that also includes two species previously assigned to the now invalid genus Pseudocetopsis (D. macilenta, D. praecox), together with three species described as new in 2005 (D. epa, D. iwokrama, D. seducta). [1]
There are currently seven recognized species in this genus: [2]
Denticetopsis species are distributed in northern South America where they are found distributed between Venezuela, Guyana and Brazil.
Denticetopsis can be distinguished from other genera of Cetopsinae by a number of characteristics. The margin of the caudal fin is either shallowly forked and symmetrical or obliquely truncate. The outer most rays are no more than one and one-half times the length of the inner most rays; in other genera of Cetopsinae, these rays are one and three-quarters to two times the length of the innermost rays. The medial most pelvic-fin ray has a membranous attachment to the body for the basal third to fourth of its length instead of the basal-most half of its length. [1]
The possession of a first pectoral-fin ray that is spinous for the basal one-half of its length further separates Denticetopsis from Cetopsis and Paracetopsis, both of which lack a spinous first pectoral-fin ray. Denticetopsis is further distinguished from Cetopsidium in the lack of the dorsal-spine locking mechanism and in the having a lateral line extending either only onto the abdomen or distinctly further posteriorly onto the caudal peduncle, instead of terminating above the base of the anal fin. [1]
Most Denticetopsis have a moderately elongate body (though moderately stout in D. macilenta and deep in D. royeroi) that is slightly compressed (laterally or transversely, depending on species) anteriorly and becoming progressively distinctly compressed posteriorly. The body depth at the dorsal fin origin is usually about one-quarter of the fish's standard length, but can be as low as one-fifth and as high as almost one-third. In most species, the lateral line is complete, unbranched in midlateral, extending from the vertical through the pectoral fin base to the caudal peduncle; however, in D. royeroi and D. sauli, it is incomplete, interrupted, and restricted to the abdomen. The dorsal profile of the body tends to be nearly straight to slightly convex; the ventral profile is slightly convex to convex at the abdomen and is usually approximately straight but posterodorsally slanted along the base of the anal fin. [1]
Except for D. macilenta which has a distinctly rounded head and snout, the head of Denticetopsis species in profile is acutely triangular overall with a bluntly pointed snout. The eyes are situated on the sides of the head and are visible from above but not from below. The mouth is inferior, the width from approximately one-half to two-thirds of the length of the head. In most species of Denticetopsis, the medial mental barbels are slightly shorter than the lateral mental barbels, with the latter approximately equal in length to the slender maxillary barbels. However, in C. sauli both pairs of mental barbels are approximately the same length and shorter than the maxillary barbels, and in C. royeroi all three pairs of barbels are approximately the same length. [1]
The dorsal fin is moderately large overall. The dorsal fin spinelet is absent. The anal fin base is usually moderately long but may be long. The pelvic fins are usually moderate but may be moderately long, though in D. sauli they are short. The pectoral fin length is about one-half the length of the head length. [1]
Denticetopsis species range from 1.8–6.7 centimetres (.71–2.6 in) SL. [2]
Sexual dimorphism in the shape of the dorsal, pectoral, and anal fins has not been described in species of Denticetopsis, despite the presence of these traits in Cetopsis and Cetopsidium. It is possible that male D. praecox reach sexual maturity at a smaller size than females of the same species. [1]
D. praecox have been found in a cobble-pebble habitat of black water streams that ranged in pH from 4.3–5.0. Stomachs of two examined specimens of this species contained larval chironomids and other larval insect remains. [1]
The Cetopsidae are a small family of catfishes, commonly called the whale catfishes.
The stream catfishes comprise the family Akysidae of catfishes.
This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes.
Phreatobius is a genus of very small catfishes from tropical South America.
Auchenipterichthys is a genus of driftwood catfishes found in South America.
Helogenes is a genus of whale catfish found in tropical South America.
Cetopsidium is a genus of catfishes of the family Cetopsidae.
Paracetopsis is a genus of whale catfishes found in tropical South America.
Cetopsis is a genus of catfishes of the family Cetopsidae.
Synodontis polli, known as Poll's synodontis, is a species of upside-down catfish endemic to the Democratic Republic of the Congo, Burundi, Zambia, and Tanzania, where it is only known from Lake Tanganyika. It was first described by Belgian ichthyologist Jean-Pierre Gosse in 1982, from specimens collected at multiple points along the shore of Lake Tanganyika.
Entomocorus is a genus of catfishes of the family Auchenipteridae.
Denticetopsis praecox is a species of whale catfish endemic to Venezuela where it is known from the Baria River of the upper Rio Negro basin. This species grows to a length of 5.3 cm.
Denticetopsis royeroi is a species of whale catfish endemic to Venezuela where it is only known from the holotype collected in a tributary to the upper Rio Negro. This species grows to a length of 1.8 cm.
Denticetopsis seducta is a species of whale catfish endemic to Brazil where it has a relatively wide, albeit scattered, distribution in the central and western portions of the Amazon basin and possibly the southwestern portions of the Orinoco River basin; it is relatively disjunct from the other species of Denticetopsis. It grows to a length of 5.1 cm.
Synodontis multimaculatus, known as the dotted synodontis, is a species of upside-down catfish that is native to the Democratic Republic of the Congo where it is found in the Ubangi River. It was first described by British-Belgian zoologist George Albert Boulenger in 1902, from a specimen collected in the Ubangi River in Mobayi-Mbongo, the Democratic Republic of the Congo. The species name multimaculatus is derived from the word multi, meaning many, and the Latin word maculatus, meaning spots, referring to the many spots on the fish.
Synodontis lucipinnis is a species of upside-down catfish endemic to Zambia, where it is only known from the Musende Rocks area (Mpulungu) of Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006. The species name "lucipinnis" is derived from a combination of the Latin luci, meaning bright or clear, and the Latin pinnis, meaning fin. This refers to the light coloration in a patch on the base of the fins of this species.
Astyanax microschemos is a species of characid fish from Brazil. It belongs to the A. scabripinnis species complex and differs from other species outside it by having a lower number of branched anal fin rays and its shallow body depth being about 26.9-29.7 vs more than 35% of its standard length (SL). Compared to species of its own complex, it can be distinguished by the combination of its shallow body depth, and smaller interorbital width. The species name comes from the Greek mikroschemos, meaning "low stature", which refers to the shallow body depth of the animal.
Deuterodon pelecus is a species of characid fish from Brazil. It can be distinguished from other species by: its body depth ; its short and pointed snout smaller than the orbital diameter; and a reduced number of branched anal fin rays. D. pelecus also differs from members of its genus by its characteristic color pattern. It possesses a single humeral spot that is constricted to the region above the lateral line; at the same time it shows a conspicuous midlateral body stripe from opercle to the caudal fin base, an autapomorphy of this precise species. Other Deuterodon species have a humeral spot that is vertically or horizontally elongate and have the midlateral stripe becoming faint near that humeral spot. The species name is derived from the Greek pelekus, meaning "axe", referring to the pigmentation shape resulting from the adjoinment of the humeral spot with the midlateral stripe.
Guyanancistrus nassauensis is a species of catfish belonging to the family Loricariidae, the suckermouth armored catfishes. It is discovered in 2005 and formally described in 2018. G. nassauensis is a rare species, highly endemic to the Nassau Mountains in Suriname, and is threatened with extinction by proposed or ongoing mining activities.
Cetopsis candiru, also known as candiru, candiru açú, candiru cobra or canero, is a carnivorous species of whale catfish found in the Amazon basin of Peru, Brazil and Bolivia. Similar to Cetopsis coecutiens, Cetopsis candiru is a large species of the genus Cetopsis and a widespread scavenger, known for its voracious feeding and the habit of burrowing into the carcasses of dead animals and humans. Despite its name, it is not closely related to the bloodsucking Candiru.