The blob sculpin (''Psychrolutes phrictus'') is a species of deep-sea fish of the family

Psychrolutidae The fish family Psychrolutidae (commonly known as blobfishes, toadfishes, flathead sculpins, tadpole sculpins,) contains over 35 recognized species in 8 genera. This family consists of bottom-dwelling marine sculpins shaped like tadpoles, with l ...

. It feeds mainly on

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s, and

sea pen Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; 35 extant genera, and it is estimated that of 450 described species, around 200 are valid. Sea pens have a co ...

s. It lives off the

continental shelves A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

in very deep water (839–2800 m) in the

North Pacific Ocean North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...

by the coasts of

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, the

Bering Sea The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...

, and

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. When the female lays eggs the adult fish guard the nest.

Description

Maximum length is . The head is broad and flattened, the eyes are large and widely separated, and the mouth is curved with fleshy lips. There is no spine in front of the operculum (the bony flap that covers the gills), the branchiostegal membranes are fused to the isthmus (the fleshy projection separating the gill openings), and there are many small

cirri Giovanni Battista Cirri (1 October 1724 – 11 June 1808) was an Italian cellist and composer in the 18th century. Biography Cirri was born in Forlì in the Emilia-Romagna Region of Italy. He had his first musical training with his brother ...

(fleshy threads) scattered over the head and body. The operculum is poorly ossified and is covered by a gelatinous layer. Behind the head, the body tapers rapidly to the caudal peduncle and there is a gelatinous layer between the skin and the muscle. The dorsal fin has eight spines and nineteen to twenty soft rays, and the anal fin has no spines and twelve to fourteen soft rays. The pectoral fins are broad and in larger individuals, have fleshy pads near their tips. The upper parts of this fish are grey or black and the underparts pale, with some indistinct mottling. It has 8 spines.

Distribution

The blob sculpin is native to the northeastern Pacific Ocean where it is found on or near the seabed at depths from .

Ecology

Aggregations of blob sculpins have been observed by using a

remotely operated underwater vehicle A remotely operated underwater vehicle (technically ROUV or just ROV) is a tethered underwater mobile device, commonly called ''underwater robot''. Definition This meaning is different from remote control vehicles operating on land or in the ai ...

. The fish were at depths between on the Gorda Escarpment off the coast of California. They spaw
adhesive eggs
onto limestone-like rocks in the deep sea, and are known to brood large pinkish eggs in nests, actually lying on the eggs or in contact with them in many instances. The eggs were free of sediment which makes it likely the adults were actively fanning them, the first known example of parental care in egg-laying deep sea fishes. Scattered around and among the sculpins were octopuses in the genus '' Graneledone'', also brooding their eggs. About half the octopuses were within 5 metres of an adult or breeding sculpin. At one site, 84 sculpins and 64 nests were observed as well as numerous brooding octopuses; the researchers described it as a "reproductive hot spot". The diet of this fish consists mainly of such invertebrates as

s and gastropod molluscs. Other items consumed include

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothuria ...

s and fish. Some of the species of fish are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

but researchers think they must have been swimming close to the seabed when consumed because the morphology of the blob sculpin is typical of a bottom dwelling fish. It is the

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

of skin parasites such as the

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 '' Chondracanthus yanezi'' and '' Neobrachiella amphipacifica''.

References

{{Authority control Psychrolutidae Fish described in 1978