Phronima sedentaria is a species of amphipod crustaceans found in oceans at a depth of up to 1 km (0.6 mi). They are large in size relative to other members of the family Phronimidae.[3] Individuals may be found inside barrel-like homes, created most commonly from the tunics of select species of tunicate, where they rear their young.[4] P. sedentaria is known to employ multiple feeding strategies and other interesting behaviors, including daily vertical migration.[4][5] The species is also known by the more common names “pram bug” and “barrel shrimp.”
Phronima sedentaria is the largest and most abundant species in the family Phronimidae.[3][4] Sexual dimorphism is reflected between male and female members in the more extended and prominent antennae of the males relative to the short, reduced ones of females. More obviously, the size discrepancy between males and females distinguishes them further. Females measure up to 42 mm (1.7 in) long, while males are only 15 mm (0.6 in) long.[6] This species also possesses a complex optical system which involves the use of two sets of compound eyes.[4] Both sets use bundles of crystalline cones to process visual information: one set faces ventrally and one set faces dorsally.[4]
Phronima sedentaria is found in temperate, subtropical, and tropical waters of all the world's oceans, including the Mediterranean Sea.[2] It is usually found in midwater pelagic habitats, but can be found migrating all the way to the surface.[7]
Phronima sedentaria most commonly exhibits a symbiotic relationship with tunicates of the genera Pyrosoma spp., Doliolum spp., and Salpa spp.[8] It is not entirely certain how to classify the symbiotic relationship between P. sedentaria and its hosts, as instances of commensalism, parasitism, and predation have all been observed. However, some research has suggested that the majority of suborder Hyperiidea members exhibit parasitic behavior.[9][10][11] Females of P. sedentaria live in the barrel-like bodies of salps, pyrosomes, and cnidarians,[3] and use their strong pleopods to propel their homes through the water. They can somersault rapidly in their barrels, thus quickly changing direction. However, speed is reduced by a factor of three to four when swimming while inside a barrel compared to swimming without one.[12] The shape of the barrel is generally asymmetrical, with one opening three times larger than that of the other.[12] In order to construct their barrels, females first locate a suitable salp, pyrosome, or cnidarian host and either cut into the host or enter through an existing opening. Once inside, the female consumes the organism within and carve out the gelatinous inside, leaving nothing but the tunic. The cells on the tunic layer may serve various functions for the P. sedentaria, including protection from UV light, storage of acid, and defense against microorganisms, like bacteria.[13] In laboratory experiments with restricted access to potential hosts, females have additionally displayed competition for barrels.[4]
While certain prey (salps, pyrosomes, and cnidaria) have additional uses for P. sedentaria in hosting their young and providing feeding platforms, the species is also carnivorous on zooplankton, krill, arrowworms, and other crustaceans.[4][14] P. sedentaria use different feeding techniques depending on the food source, but the leading sets of pereiopods (front legs) are primarily used in all cases. Mouth pieces, such as the mandible, maxillipeds, and maxillae, manipulate the food into small pieces which are then able to fit through the esophagus.[4] Feeding preferentially occurs at nighttime when members of this species undergo a vertical migration of around 200–350 meters to the ocean's surface.[5] Research has shown this species is susceptible to temperature fluctuations outside of the range 8-25 degrees Celsius (46-77 degrees Fahrenheit), which explains the desire for cooler deep water (300–600 meters deep) throughout the day and warmer shallow waters (0–25 meters deep) at night.[5][15] P. sedentaria typically migrate to hypoxic areas (such as the Oxygen Minimum Zone) during the day, causing low metabolic rates and physical activity.[15]
Known predators of P. sedentaria include the longnose lancetfish,[16] European flying squid,[17] Pacific pomfret,[18] albacore,[8] and skipjack tuna.[8]
Female Phronima sedentaria are capable of producing up to 600 eggs at a time.[8] Juveniles spend their early development within the mother in a specialized pouch called the marsupium. After finding a suitable host, the female begins to transform the barrel into a nursery for its young. She uses her pleopods and anterior pereiopods to remove offspring from the marsupium, while her posterior pereiopods maintain stability and grasp onto the barrel.[4] Once inside, the young organize themselves into a medial ring around the interior of the barrel. This shape is maintained until the mother delivers food, which the offspring then feed on and return to formation afterwards.[4] Young P. sedentaria use the barrel as another food source. The offspring of P. sedentaria develop within their barrel homes until reaching prematurity, after which they are able to feed and survive independently.[3] Development is characterized by growth stages in which molting occurs.[3] Each molt adds a new segment to the sets of pleopods in the rear. The emergence of sexual dimorphism occurs soon after prematurity.[3]
{{cite web}}: CS1 maint: url-status (link) Phronima sedentaria is a species of amphipod crustaceans found in oceans at a depth of up to 1 km (0.6 mi). They are large in size relative to other members of the family Phronimidae. Individuals may be found inside barrel-like homes, created most commonly from the tunics of select species of tunicate, where they rear their young. P. sedentaria is known to employ multiple feeding strategies and other interesting behaviors, including daily vertical migration. The species is also known by the more common names “pram bug” and “barrel shrimp.”
Phronima sedentaria
Le tonnelier de mer (Phronima sedentaria) aussi nommé phronime est une espèce d'amphipode parasite des abysses européens. Sa principale zone d'habitat se trouve à environ un kilomètre de profondeur.
La taille moyenne des femelles est de l'ordre de 42 millimètres tandis que les mâles, trois fois plus petits, mesurent environ 15 mm.
Phronima sedentaria se trouve dans les eaux tempérées, tropicales et subtropicales de tous les océans du monde, incluant la Méditerranée. Il vit entre deux eaux dans les milieux pélagiques mais peut migrer jusqu'à la surface. Il s'accroche à une ascidie (salpe) ou à une méduse dont il dévore l'intérieur avant d'utiliser sa peau transparente comme《 maison flottante 》pour lui même et ses petits.
Le Tonnelier de mer est carnivore et se nourrit de zooplancton, de krill et de vers de mer.
La phronime est à même de se rendre invisible[1].
Phronima sedentaria
Le tonnelier de mer (Phronima sedentaria) aussi nommé phronime est une espèce d'amphipode parasite des abysses européens. Sa principale zone d'habitat se trouve à environ un kilomètre de profondeur.
Phronima sedentaria é unha especie de crustáceo anfípodo que habita no océano a unha profundidade de até 1 quilómetro.
As femias miden até 42 mm de longo, mentres que os machos miden só 15 mm de longo.[3]
P. sedentaria habita en augas temperadas, subtropicais e tropicais de tódolos océanos do mundo, incluíndo o mar Mediterráneo.[2] É común atopalo en hábitats peláxicos, mais tamén é posible atopalo durante as migracións preto da superficie. Rexistrouse a a súa presenza nas augas de Galicia, cun achado de exemplares nas praias de Vigo en febreiro de 2019.[4]
As femias de P. sedentaria viven en corpos en forma de barril de salpas e pirosomas, e usan os seus fortes pleópodos para impulsarse a través del agua. A especie é carnívora e aliméntase de zooplancto, krill e vermes mariños.[5]
Phronima sedentaria é unha especie de crustáceo anfípodo que habita no océano a unha profundidade de até 1 quilómetro.
Phronima sedentaria is een vlokreeftensoort uit de familie van de Phronimidae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1775 door Forskal.
Bronnen, noten en/of referenties
Phronima sedentaria er en art av frittsvømmende, storøyde tanglopper. De ser ut som små gjennomsiktige reker. De finnes mest på store dyp, og er ca. 2,5 cm lange. Phronima spiser dyreplankton.
Phronima sedentaria bruker ofte døde salper som hus. Phronima tjente som inspirasjon til H.R. Gigers Alien-monster.
Arten lever i Atlanterhavet inklusive Norskehavet.
Phronima sedentaria er en art av frittsvømmende, storøyde tanglopper. De ser ut som små gjennomsiktige reker. De finnes mest på store dyp, og er ca. 2,5 cm lange. Phronima spiser dyreplankton.
Phronima sedentaria bruker ofte døde salper som hus. Phronima tjente som inspirasjon til H.R. Gigers Alien-monster.
Arten lever i Atlanterhavet inklusive Norskehavet.
