''Sebastes diploproa,'', the splitnose rockfish, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

belonging to the subfamily

Sebastinae Sebastinae is a subfamily of marine fish belonging to the family Scorpaenidae in the order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpionfishes, sea ruffes and rockcods. D ...

, the rockfishes, part of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venom ...

. It is found in the northeastern Pacific Ocean.

Taxonomy

''Sebastes dallii'' was first formally described as ''Sebastichthys diploproa'' in 1890 by the American

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

Charles Henry Gilbert Charles Henry Gilbert (December 5, 1859 in Rockford, Illinois – April 20, 1928 in Palo Alto, California) was a pioneer ichthyologist and Fisheries science, fishery biologist of particular significance to natural history of the western Unit ...

with the type locality given as off

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

. Some authorities place this species in the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Allosebastes''. The specific name ''diploproa'' means "double prowed", probably a reference to the tooth bearing knob in the front of each upper jaw forming a deep notch between jaws.

Description

''Sebastes diploproa'' is a relatively small stockfish with a deep body a deep-body and large eyes. Its upper jaw has a distinct incision which separates two tooth-bearing knobs on each side. There are robust spines on the head with the nasal, preocular, postocular, tympanic and parietal spines being present and there are no supraocular, coronal and nuchal spines. The dorsal fin has 13 spines and 11-14 soft rays while the anal fin 3 spines and 5-8 soft rays. The caudal fin is slightly forked. This species attains a maximum total length of and the maximum published weight of . The adults are light pink, pale orange or white with darker pink, orange or red blotches or bars on the upper body, head and fins. The spines in the dorsal fin may be tipped with white while the membranes between them can have dark edges.

Distribution and habitat

''Sebastes diploproa'' Is found in the eastern Pacific Ocean off the western coast of North America from the Alaska Peninsula south to Cedros Island off Baja California. It occurs at depths between . The pelagic juveniles live underneath floating mats of

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwat ...

at the surfacesettling on the seabed as adults on soft substrates.

Biology

''Sebastes diploproa'' has a reported maximum age of 86 years old. This is a ovoviviparous species in which fertilisation is internal. The smaller females have a fecundity of around 14,000 eggs, while larger females have up to 255,000 eggs. This species releases larvae through out the year. The larvae feed on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and the larger juveniles feed on

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

s caught among the kelp mats. Adults feed on

krill Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in n ...

, amphipods,

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s, decapods and fishes. The juveniles have been found to have

phaeohyphomycosis Phaeohyphomycosis is a diverse group of fungal infections, caused by dematiaceous fungi whose morphologic characteristics in tissue include hyphae, yeast-like cells, or a combination of these. It can be associated an array of melanistic filamento ...

caused by infection with fungi of the genus '' Devriesia'', the first case discovered of this type of fungi causing disease in animals.

Fisheries

''Sebastes diploproa'' are caught by commercial fisheries in the United States, mainly in deepwater fisheries targeting rockfish species, and other demersal fishes, on the continental slope. In these mixed species landings the rockfishes are not consistently sorted to species, and the catch is estimated by sampling species compositions to mixed rockfish landings in port. 90% of the annual catch is from trawlers and 80% of this catch is landed in California and 10% of splitnose rockfish landed are caught by net or hook and line commercial fisheries. This species is not a frequent target for recreational fishers.

References

External links

* * {{Taxonbar, from=Q1879097 diploproa Taxa named by Charles Henry Gilbert Fish described in 1890