Paralarvae (sg.: paralarva) are young cephalopods in the planktonic stages between hatchling and subadult. This stage differs from the larval stage of animals that undergo true metamorphosis. [1] Paralarvae have been observed only in members of the orders Octopoda and Teuthida. [2]
The term was first introduced by Richard E. Young and Robert F. Harman in 1988. [2]
Paralarvae usually spend an uncertain amount of time in the plankton and then typically descend to an adult habitat in the mesopelagic or bathypelagic zone. Their population abundance is dependent on the variation of mortality rates during the planktonic period.
A larva is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The Chiroteuthidae are a family of deep-sea squid, generally small to medium in size, rather soft and gelatinous, and slow moving. They are found in most temperate and tropical oceans, but are known primarily from the North Atlantic, North Pacific, and Indo-Pacific. The family is represented by approximately 12 species and four subspecies in four genera, two of which are monotypic. They are sometimes known collectively as whip-lash squid, but this common name is also applied to the Mastigoteuthidae, which are sometimes treated as a subfamily (Mastigoteuthinae) of Chiroteuthidae.
Pyroteuthidae is a family of squids. The family comprises two genera. Species are diurnally mesopelagic, migrating into surface waters during the night. The family is characterised by the tentacles, which have a permanent constriction and bend near the base; and photophores occurring on the tentacles, eyeballs, and viscera. Members reach mantle lengths of 23–50 mm. Paralarvae of the family are common around the Hawaiian Islands, with up to 17% of collected specimens in the area belonging to Pyroteuthidae.
A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells.
Bathothauma lyromma, the lyre cranch squid, is a highly modified species of glass squid from the family Cranchiidae with a distribution which encompasses most of the world's oceans from the tropics to high latitudes.
Pterygioteuthis giardi is a species of squid in the family Pyroteuthidae. It is known as the roundear enope squid. The specific name honors the French zoologist and marine biologist Alfred Mathieu Giard (1846-1908).
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
The Antarctic neosquid is the only neosquid in the genus Alluroteuthis. The tentacles are relatively short compared to the arms.
Ichthyoplankton are the eggs and larvae of fish. They are mostly found in the sunlit zone of the water column, less than 200 metres deep, which is sometimes called the epipelagic or photic zone. Ichthyoplankton are planktonic, meaning they cannot swim effectively under their own power, but must drift with the ocean currents. Fish eggs cannot swim at all, and are unambiguously planktonic. Early stage larvae swim poorly, but later stage larvae swim better and cease to be planktonic as they grow into juveniles. Fish larvae are part of the zooplankton that eat smaller plankton, while fish eggs carry their own food supply. Both eggs and larvae are themselves eaten by larger animals.
Octopus aquaculture describes the captive-raising of octopuses and commercial sale of their meat. A complex and labor-intensive form of farming, octopus aquaculture is being driven by strong market demand in the Mediterranean and in South American and Asian countries. Annual global demand for octopus more than doubled from 1980 to 2019, from roughly 180,000 to about 370,000 tons. The supply of octopus has been constrained by overfishing in many key fisheries and proponents of farming suggest human-induced culturing could help restock natural populations. Opponents of the nascent industry argue that cephalopod intelligence and emotional capacity, as well as the solitary and carnivorous character of octopuses, make them particularly ill-suited to intensive, captive breeding. Commercial sale may stimulate market demand, hastening rather than offsetting the decline in wild stocks. An announcement that a Spanish firm would begin octopus aquaculture as early as 2022 prompted ethical and scientific controversy.
Teuthowenia megalops, sometimes known as the Atlantic cranch squid, is a species of glass squid from the subarctic and temperate waters of the northern Atlantic Ocean. They are moderately sized squid with a maximum mantle length of 40 cm (16 in). Their very large eyes are the source for the specific name megalops. Like other members of the genus Teuthowenia, they are easily recognizable by the presence of three bioluminescent organs (photophores) on their eyeballs.
Fish go through various life stages between fertilization and adulthood. The life of a fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish.
Pinnoctopus cordiformis is a species of octopus found around the coasts of New Zealand. It is one of the most common species of octopus in the country.
Macrotritopus is a poorly known genus of octopuses in the family Octopodidae. As it stands, Macrotritopus contains one valid described species, Macrotritopus defilippi. Two poorly described, unresolved taxa which are known only from planktonic hatchlings have been tentively assigned Macrotritopus equivocus and M. scorpio, as well as a further three undescribed Indo-Pacific species. Macrotritopus was originally described from a single juvenile specimen which was named Macrotritopus equivocus notable for having an elongated third arm. This specimen gave the name Macrotritopus larva to this form of paralarva which was misidentified as the newly hatched juveniles of Scaeurgus unicirrhus. When the eggs of M. defilippi, which were kept in captivity, hatched and the resultant larvae were observed to be of the Macrotritopus larval type then the juveniles were connected with the adults. This means that the type species of Macrotritopus is a juvenile and that M. defillipi is the only species where the adult form is known. The presence of Macrotritopus larvae” off South Africa and the Indo‑West Pacific from Australia to Hawaii indicates that there may be a number of yet to be described species within this genus.
Taonius belone is a glass squid belonging to the genus Taonius from the family Cranchiidae. It occurs in the northern subtropical and in the tropical or equatorial waters of the Pacific Ocean and the Indian Ocean.
Richard E. Young is a teuthologist. He is an Emeritus Professor of Oceanography at the University of Hawaii's School of Ocean and Earth Science and Technology.
Lampadioteuthis megaleia is a small, colorful squid, the only species in the only genus in the monotypic family Lampadioteuthidae. It is sometimes known as the wonderful firefly squid. It was formerly classified in the family Lycoteuthidae, but differs from them mainly by having a hectocotylus in the males and by the possession of a rostrum on the gladius.
Neoteuthis is a monotypic genus of squid, the sole member is Neoteuthis thielei, from the family Neoteuthidae. This species has long tentacular clubs measuring 60% of the mantle length and fins which are 70% of its mantle length. It has a proximal locking-apparatus for the club which is restricted to manus, which in turn has proximal suckers which are circular. It has been recorded from the South Atlantic Ocean, North Atlantic Ocean, near the Canary Islands and North Pacific Ocean, north of Hawaii. The paralarvae and juveniles are found in the epipelagic to mesopelagic zones while adults occur in the mesopelagic to bathypelagic zones.
A micronekton is a group of organisms of 2 to 20 cm in size which are able to swim independently of ocean currents. The word 'nekton' is derived from the Greek νήκτον, translit. nekton, meaning "to swim", and was coined by Ernst Haeckel in 1890.
Octopus sinensis is a mollusk belonging to the class Cephalopoda. Octopus sinensis is a well-known shallow-water benthic octopus species found in the coastal, temperature waters of South Korea, China, and Japan, with the species name, sinensis being Latin for Chinese. Octopus sinensis is closely related to the Atlantic and Mediterranean common octopus, Octopus vulgaris. Because of the morphological similarities, O. sinensis was considered synonymous with Octopus vulgaris until 2017. Octopus sinensis are carnivores that prey upon on many shallow-water animals such as crustaceans and mollusks.