These animals have a large body cavity, a closed circulatory system, a complex brain, a highly responsive nervous system, and head with large & complex eyes. They are small; maximum length (excluding tentacles) is 10 cm. Their bodies are short and rounded at the posterior end. They have 8 short arms (each with 2-4 ros of suckers) and 2 long arms, which can be almost entirely withdrawn into the body. The shell, or "pen," is internal, slender, and very thin and delicate. These squid also have large, semi-circular fins on the middle of the sides of the body.
Other Physical Features: ectothermic ; bilateral symmetry
These animals are swim freely in the marine environment. Inhabit shallow reef areas, sand and rubble bottoms to depths of more than 5000m.
Aquatic Biomes: reef ; coastal
Northern Atlantic Ocean and the Pacific Ocean.
Biogeographic Regions: atlantic ocean (Native ); pacific ocean (Native )
Highly adapted for raptorial feeding and a carnivorous diet. Locate prey with their highly developed eyes, capture it with the appendages.
The sexes are separate. Males impregnate the females with a modified arm tip that transfers sperm. The male grasps the female from the ventral side with the long tentacles. Animals are oriented so that both heads face the same direction. Male's hectocotylus, its left first arm, is inserted into the female's mantle cavity, where it deposits the spermatophores.
Rossia pacifica, also known as the stubby squid, is a species of bobtail squid native to the northern Pacific Ocean. It usually occurs in winter on sandy slopes away from strong currents in moderately shallow water. In summer it moves to deeper water where it breeds. The female cements the egg capsules under a stone or in some other concealed location, and both male and female die soon after breeding.
Two subspecies are recognised: - [2]
The stubby squid is a small species growing to a maximum mantle length of about 5 cm (2.0 in) and a total length of 11 cm (4.3 in), with females being larger than males. The head bears eight short arms, a pair of retractable tentacles and two large eyes. The first pair of arms is shorter than the others and the third pair the longest. The arms are circular in cross-section and each bears up to four rows of suckers on the middle section and two rows elsewhere. The tentacles have club-shaped tips with suckers and retract into pits in the head. They can be as long as the body when fully extended. The mantle (body) is not fused to the head and is flattened dorso-ventrally and rounded at the back. It does not contain the cuttlefish bone typical of cuttlefish in the family Sepiidae. There are two large semi-circular fins with wide bases on either side of the mantle. The upper surface of this bobtail squid is normally a reddish-brown colour with a scattering of small brown or yellowish spots, but can change to greyish-green when the animal is startled.[3]
The stubby squid is native to the northern Pacific Ocean. Its range extends from Korea, Japan and the Bering Sea to the western coast of North America, as far south as California. Its depth range is 20 to 1,350 m (66 to 4,429 ft). Monterey Bay Aquarium Research Institute (MBARI) researchers reported a sighting of a stubby squid even deeper in the ocean.[4] In Puget Sound it is seen in winter in regions of sloping muddy sand away from strong currents at less than 300 m (984 ft) but moves into deeper water in the summer.[5] When found in coastal regions it has been typically reported in the sub-tidal zone (16–370 m) and has been found at night swimming at shore in the intertidal zone.[6] It has been found to be able to live and survive in highly polluted urban west coast bay areas of the United States.
The stubby squid usually rests on the seabed and moves around, either by movement of its fins or by expelling a jet of water from its body cavity through a movable funnel just below the head. When disturbed, it can leave behind a thick blob of black ink as it speeds away by jet propulsion. It is nocturnal and spends the day semi-buried in soft sediment on the seabed. To submerge itself, it directs a stream of water at the sand to create a funnel-shaped depression, then it settles in the hollow and scoops sand over itself with a pair of arms, just leaving the eyes exposed.[5] While immobile, it folds its arms under its head.
The stubby squid has a hardened beak it uses to eat, its mouth is centered on the body and all tentacles connect at this point as well. It has adapted to a carnivorous diet by using a raptorial style of hunting. The squid will use its specialized eyes to locate the prey and then attack with its tentacles.[7] More than 80% of their diet is shrimps but they also consume small crabs, mysida, fish and other cephalopods.[3]
Breeding takes place in late summer and autumn in deep water. The male will transfer the spermataphores (bundles of sperm) into the female's mantle cavity with his hectocotylus, first left arm.[7] The mature male and female die soon after breeding, having lived for about two years.[4] The average female will deposit between twenty-five and fifty eggs in clusters, attaching them to the underside of stones, clams or faissal manda. The capsules are creamy-white, hard and durable they take four to nine months to hatch and receive no additional care. The egg itself (4–5 mm in diameter), is contained in a larger capsule (8 mm by 15 mm).[6] The juveniles that emerge are miniature versions of the adults.[5]
Rossia pacifica, also known as the stubby squid, is a species of bobtail squid native to the northern Pacific Ocean. It usually occurs in winter on sandy slopes away from strong currents in moderately shallow water. In summer it moves to deeper water where it breeds. The female cements the egg capsules under a stone or in some other concealed location, and both male and female die soon after breeding.
Sépiole du Pacifique boréal
Rossia pacifica, communément appelé la Sépiole du Pacifique boréal, est une espèce de seiches de la famille des Sepiolidae, originaire du nord de l'Océan Pacifique. Cette espèce se rencontre pendant l'hiver sur les pentes sablonneuses peu profondes et aux courants modérés. Elle migre en été vers des eaux plus profondes afin de s'y reproduire. La femelle colle ses œufs sous des récifs ou des pierres. La femelle et le mâle meurent ensuite rapidement après l'accouplement.
La Sépiole du Pacifique boréal est une espèce à la taille assez réduite. Les spécimens de cette espèce peuvent mesure de 5 à 11 cm de long. Le dimorphisme sexuel se limite à une différence de taille entre les sexes, les femelles étant généralement plus grandes que les mâles.
Elle possède huit bras courts, une paire de tentacules rétractables et deux grands yeux. Ses bras peuvent comporter jusqu'à quatre rangées de ventouses.
La Sépiole du Pacifique boréal est originaire du nord de l'Océan Pacifique. Son biotope s'étend des côtes de la Corée, en passant par le Japon et la Mer de Béring à la côte ouest de l'Amérique du Nord jusqu'au sud de la Californie.
Il est possible de la rencontrer sur les fonds marins à des profondeurs allant de 20 m en hiver à près de 1 350 m en été lors de la période de reproduction.
La Sépiole du Pacifique boréal repose généralement sur les fonds marins et se déplace grâce aux ondulations de ses ailettes ou, en cas de danger, par l'expulsion de l'eau de son manteau (muscle servant à propulser l'eau hors de son corps)
Si elle est dérangée par un prédateur, elle peut également propulser un épais nuage d'encre pour prendre la fuite.
La reproduction a lieu en fin d'été et à l'automne dans les eaux profondes. La femelle dépose jusqu'à cinquante œufs en petits groupes, qui sont attachés sous des pierres, des coquillages ou des algues. Les œufs sont de couleur blanc-crème, et mesurent environ 1 cm de diamètre. Ils éclosent au bout d'une période allant de quatre à neuf mois et les juvéniles lors de leur naissance possèdent déjà toutes les caractéristiques des individus adultes.
La Sépiole du Pacifique boréal vit en moyenne deux ans et meurt après la période de reproduction.
Selon World Register of Marine Species (17 septembre 2020)[2] :
Sépiole du Pacifique boréal
Rossia pacifica, communément appelé la Sépiole du Pacifique boréal, est une espèce de seiches de la famille des Sepiolidae, originaire du nord de l'Océan Pacifique. Cette espèce se rencontre pendant l'hiver sur les pentes sablonneuses peu profondes et aux courants modérés. Elle migre en été vers des eaux plus profondes afin de s'y reproduire. La femelle colle ses œufs sous des récifs ou des pierres. La femelle et le mâle meurent ensuite rapidement après l'accouplement.
Rossia pacifica is een inktvissensoort uit de familie van de Sepiolidae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1911 door S. S. Berry.
Bronnen, noten en/of referentiesRossia pacifica Berry, 1911
Охранный статусТихоокеанская ро́ссия (лат. Rossia pacifica) — вид головоногих моллюсков рода Rossia из семейства Sepiolidae (Rossiinae).
Длина тела без щупалец до 15, а длина мантии до 8 см. Тело овальной формы, закруглённое сзади. Верхняя сторона тела красно-коричневая или зеленовато-серая с мелкими тёмно-коричневыми или лимонно-жёлтыми крапинками. Плавники овальные, с широкими основаниями. Передний край мантии не срастается с головой. На ловчих щупальцах у основания 2, в средней части и на концах 4 ряда присосок примерно одинаковых размеров. На обычных щупальцах 6—8 рядов присосок. Обе спинные руки самца преобразовываются для переноса сперматофоров.
Встречается на севере Тихого океана от Корейского полуострова до Берингова моря, от Японии до южной Калифорнии[1][2]. Живёт на глубине 20—1350 м, на илу либо илистом песке.
Охотясь днём, эта каракатица закапывается в грунт и сохраняет полную неподвижность, поджидая жертву. Ночью она охотится активно. Основа её рациона — мелкие ракообразные[3].
Брачный период приходится на лето. Самец помещает в мантийную полость самки сперматофоры 16—17 мм длиной. Самка откладывает на подводные предметы небольшую кучку круглых яиц длиной до 9 мм, покрытых плотной беловатой оболочкой.
Этот вид часто встречается в прилове траулеров. В Японии употребляется в пищу.
Тихоокеанская ро́ссия (лат. Rossia pacifica) — вид головоногих моллюсков рода Rossia из семейства Sepiolidae (Rossiinae).