''Sebastolobus'', the thornyheads, is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Sebastinae Sebastinae is a subfamily of marine fish belonging to the Family (biology), family Scorpaenidae in the Order (biology), order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpion ...

, the rockfishes, part of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family (biology), family of mostly ocean, 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 ...

. These fishes are native to the northern and eastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. They are generally found in deep waters.

Taxonomy

''Sebastolobus'' was first described as a genus 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, 35,800 species of fish had been described as of March 2 ...

Theodore Gill Theodore Nicholas Gill (March 21, 1837 – September 25, 1914) was an American ichthyologist, mammalogist, malacologist, and librarian. Career Born and educated in New York City under private tutors, Gill early showed interest in natural hist ...

in 1881 with ''Sebastes macrochir'', a species described, with its type locality given as Japan, by the German-born British ichthyologist and

herpetologist Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (in ...

Albert Gunther in 1877. It is the

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

of the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

Sebastolobini Sebastolobini is a tribe of marine ray-finned fishes belonging to the subfamily Sebastinae of the family Scorpaenidae in the order Scorpaeniformes. Many species have the common name thornyhead. Taxonomy Sebastolobini was first formally recognise ...

, one of two in the Sebastinae, a subfamily of the family Scorpaenidae. The generic name is a compound of ''

Sebastes ''Sebastes'' is a genus of marine ray-finned fish belonging to the subfamily Sebastinae part of the family Scorpaenidae, most of which have the common name of rockfish. A few are called ocean perch, sea perch or redfish instead. They are found ...

'', the original genus of the type species, and ''lobus'', "lobed", a reference to the lower rays of the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s being widened into tongue-shaped lobes.

Species

There are currently three recognized species in this genus:

Characteristics

''Sebastolobus'' thornyheads have moderately compressed bodies with relatively large head armed with 8 pairs of robust spines along its top. The eyes are large and there is a horizontal suborbital ridge which is armed with another 8-10 strong spines. They have a large number of conical teeth on the jaws with teeth on the roof of the mouth too. The single dorsal fin is incised to the rear of the spiny part. There are 15 to 17 robust and venom bearing spines in the dorsal fin, followed by between 8 and 11 soft rays. The anal fin has 3 spines and between 4 and 6 soft rays. The caudal fin is straight edged. These species have maximum lengths which vary from

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

in ''S. altevelis'' up to a

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

in ''S. alascanus''.

Distribution and habitat

''Sebastolobus'' thornyheads are found in the northern Pacific Ocean in both the eastern and western parts with

vagrants Vagrancy is the condition of wandering homelessness without regular employment or income. Vagrants usually live in poverty and support themselves by travelling while engaging in begging, scavenging, or petty theft. In Western countries, ...

extending as far south as Costa Rica. They are

demersal fish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They oc ...

es which are found over soft substrates.

Biology

''Sebastolobus'' thornyheads are

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

, unlike the rockfishes in the genus ''Sebastes'' and the females extrude gelatinous egg masses.

References

Marine fish genera Taxa named by Theodore Gill Taxonomy articles created by Polbot {{Scorpaeniformes-stub