Dromia personata, also known as the sponge crab or sleepy crab, is a species of crab found in the North Sea, the Mediterranean Sea, and connecting parts of the northeastern Atlantic Ocean.[4] Like most other epibenthic crustaceans, the biomass of this species is especially dense in the Mediterranean continental shelf.[5] It mainly resides from the lower shore to a depth of 50 meters (164 ft), often in caves.[4] Occasionally, they are found living in depths as low as 110 meters (360 ft).[5] They serve as prey for octopus, starfish, and other fish.[6] Their last two pairs of legs are positioned dorsally,[7] and are used to hold a sponge in place as camouflage.[4]
Dromia personata is a gonochoric species.[8] Courtship prior to copulation is commonly practiced through visual, olfactory, or tactile means.[8] Sperm can only be transferred directly from the male's gonopod into the ovigerous female after a molting period, when her exoskeleton has not hardened yet.[9] Females store eggs in a pleopod and can also house sperm for up to nine months.[9]
During development, the blastula forms three tissue layers: the ectoderm, mesoderm, and endoderm.[10] The mesoderm tissue produces the coelum, which gives rise to the body cavity and specialized tissues and organs.[10] Fertilized eggs hatch into larvae.[10] These undergo four zoeal stages, followed by a megalopal stage, and finally an adult stage.[8] With each molting period between these three phases, the crab gains new appendages while limbs that were formerly established become more specialized.[10]
As an arthropod, D. personata is bilaterally symmetrical.[10] The body is composed of a head, which contains the cephalon, and an elongated trunk, which consists of a thorax and abdomen.[11] From the cephalon, there are two pairs of antennae and a mandible placed anteriorly, in addition to two pairs of maxillae positioned laterally.[11] The trunk sprouts five pairs of walking legs, which are segmented medially to laterally: coxa, basis, ischium, merus, carpus, manus, and dactyl.[12] The coxa, basis, ischium are smaller aspects that serve to attach the jointed limb to the crab's body.[12]
The exoskeleton is composed of a chitin cuticle.[10] This is periodically molted when the crab undergoes ecdysis.[10] Following this shedding, other organisms or the crab itself will ingest the former shell to gain its nutrients. Most of D. personata's body is covered in tiny dark brown hairs that result in a smooth or velvet-like appearance.[13] The only exception is its cheliped tips, which are typically white or light pink in color and hairless.[13] These two chelipeds are large, equal in size and shape, and placed ventrally.[13]
Typically, crabs have eight pereiopods that are utilized for swimming: the second, third, fourth, and fifth pairs of legs.[14] However, D. personata only uses its second and third pairs for locomotion.[14] These legs are long and stout.[4] Meanwhile, it utilizes its remaining ambulatory legs, the fourth and fifth pairs, to hold sponges against the hairs of its dorsal cephalothorax.[14] These legs are sort, narrow, flat, and placed dorsally.[4]
All decapods have an internal tube that transports food through the mouth, stomach, intestine, and anus.[15] It is divided into three sections: the foregut, midgut, and hindgut.[15]
The foregut is split into the cardiac foregut and pyloric foregut.[16] They both contain ossicles, which serve the essential role of mastication.[15] The cardiac foregut is defined by its sac-shaped structure, thin walls, prepterocardiac ossicle, and postpterocardiac ossicle.[16] Meanwhile the pyloric foregut is characterized by its plates, lateral mesopyloric ossicle, and posterior uropyloric ossicle.[16]
Previous studies and staining methods were unable to differentiate the calcified structures.[16] However, recent research completed with Alizarin Red S staining has allowed them to be described with correct terminology, and for comparative analyses to be completed between decapod crustacean species to determine their phylogenetic relationships.[16]
Dromia personata is known for adhering a sponge to its back.[4] The two organisms have a symbiotic relationship where the crab is able to camouflage[4] while providing the sponge with physical protection from predators, such as fish, turtles, and sea slugs.[17] The crab prefers Halichondria panicea, Celtodoryx ciocalyptoides,[6] and sponges of the Suberites genus.[6] Upon obtaining a sponge, either when molding its first sponge or obtaining a new one following a period of molting, the fourth and fifth pairs of pereiopods tear the sponge from its edges until it is a spherical size and shape.[14] These same legs support the sponge on the crab's back.[4] As it grows, the sponge conforms to mimic the cephalothorax shape.[4]
D. personata has exhibited protective behavior for its sponge.[14] When another organism attempts to eat or steal its sponge, the host crab attacks with its chelae.[14] When concealed within a mass of other sponges, the crab is able to identify the sponge it most recently claimed.[14] In addition, it surpasses considerable physical challenges, such as lifting rocks, in order to retrieve its sponge.[14]
Dromia personata, also known as the sponge crab or sleepy crab, is a species of crab found in the North Sea, the Mediterranean Sea, and connecting parts of the northeastern Atlantic Ocean. Like most other epibenthic crustaceans, the biomass of this species is especially dense in the Mediterranean continental shelf. It mainly resides from the lower shore to a depth of 50 meters (164 ft), often in caves. Occasionally, they are found living in depths as low as 110 meters (360 ft). They serve as prey for octopus, starfish, and other fish. Their last two pairs of legs are positioned dorsally, and are used to hold a sponge in place as camouflage.
Dromia personata, la dromie, est une espèce de crabes vivant dans la mer Méditerranée, la mer du Nord et le nord-est de l'océan Atlantique.
Dromie velue, crabe-pierre, crabe-éponge, crabe-béret basque, crabe-nounours. Noms régionaux : krank-voulouz (Breton), crabe dodu (sud-ouest), tourlourou (Cotentin), oumigrana durmeiré (Provençal), crabe Moscato (bassin d'arcachon), franquet dormidor de furari (Catalan).
Crabe de forme très arrondie pouvant mesurer jusqu'à 10 cm de largeur, il est facilement reconnaissable de par son aspect trapu et le bout de ses pinces rose. Il est très facile de le confondre avec un élément rocheux, ressemblant souvent à une pierre de la couleur de la roche environnante.
La Dromie recouvre souvent son dos avec une éponge vivante qu'elle maintient avec ses pattes postérieures. C'est une espèce nocturne se déplaçant le plus souvent frontalement et assez lentement.
Fond rocheux, galerie, grotte.
Dromia personata, la dromie, est une espèce de crabes vivant dans la mer Méditerranée, la mer du Nord et le nord-est de l'océan Atlantique.
La dromia (Dromia personata (Linnaeus, 1758)) è un granchio appartenente alla famiglia Dromiidae[1] noto anche come granchio facchino o granchio dormiglione.
Lo si può incontrare in grotte o in fondali rocciosi, questa specie si può incontrare fino a 150 m di profondità. Raramente si spinge verso i litorali.
Ha l'abitudine di trasportare sul dorso una spugna che lo nasconde parzialmente e cresce con lui, ma ad una velocità inferiore; dopo alcune mute, infatti, il granchio la rimpiazza con un pezzo più ampio tagliato su misura dal substrato per mezzo delle sue chele. È prevalentemente notturno.
È una specie quasi onnivora si nutre di alghe fresche, piccoli echinodermi, attinie e detriti organici di ogni genere.
È molto sconsigliato tenere questo granchio in un acquario in quanto tende a distruggere spugne e stelle marine per nascondersi sotto di esse.[2]
La dromia (Dromia personata (Linnaeus, 1758)) è un granchio appartenente alla famiglia Dromiidae noto anche come granchio facchino o granchio dormiglione.
De wolkrab (Dromia personata) is een krab uit de familie Dromiidae, de wol-of sponskrabben. De soort is zeer zeldzaam voor de Belgische kust en is in de Nederlandse wateren voor het eerst in augustus 2016 gezien.[2]
De wolkrab heeft een sterk gezwollen, ovale carapax, waarvan de lengte maximaal 50 mm bedraagt en de breedte 65 mm. De carapax en de pereopoden zijn bedekt met korte bruine haren. Deze krab draagt vaak een spons of een zakpijpenkolonie op zijn rugschild als camouflage. De schaarpoten zijn krachtig ontwikkeld en hebben typisch roze chelae (vingers van de schaarpoten). De twee laatste paar pereopoden zijn subchelaat.[3]
De wolkrab komt voor op stenige en rotsachtige bodems, vanaf de getijdenzone tot op 100 m diepte (meestal tussen 10 en 30 m). Het is een niet algemene Oost-Atlantische soort die gevonden wordt van de zuidelijke Noordzee zuidwaarts tot voor Senegal. Ze is ook gevonden voor de Canarische Eilanden, de Azoren, Madeira en in de Middellandse Zee.[4]
De rugcamouflage zou een bescherming bieden tegen predatie door inktvissen (Ingle, 1983).[5]
Er is weinig bekend over het dieet van de wolkrab.
De wolkrab (Dromia personata) is een krab uit de familie Dromiidae, de wol-of sponskrabben. De soort is zeer zeldzaam voor de Belgische kust en is in de Nederlandse wateren voor het eerst in augustus 2016 gezien.
Dromia personata là một loài cua sinh sống ở Biển Bắc, Địa Trung Hải, và những phần tiếp nối với vùng đông bắc Đại Tây Dương.[4] Chiều dài mai của nó có hể đạt đến 53 milimét (2,1 in), và sống chủ yếu từ bờ biển đến vùng nước có độ sâu 8 mét (26 ft),[5] có trường hợp đến 100 mét (330 ft), và thường lẫn trốn trong hang.[4]
Dromia personata là một loài cua sinh sống ở Biển Bắc, Địa Trung Hải, và những phần tiếp nối với vùng đông bắc Đại Tây Dương. Chiều dài mai của nó có hể đạt đến 53 milimét (2,1 in), và sống chủ yếu từ bờ biển đến vùng nước có độ sâu 8 mét (26 ft), có trường hợp đến 100 mét (330 ft), và thường lẫn trốn trong hang.
Dromia personata (лат.) — вид крабов из семейства Dromiidae, обитающий в Северном море, Средиземном море и на северо-востоке Атлантического океана. В некоторых изданиях называется «Волосатый краб»[1]. Длина карапакса составляет 53 мм. Обитает, главным образом, вблизи побережий на глубине до 8 м, иногда до 100 м, часто в пещерах. Две последние пары конечностей размещены на спине таким образом, чтобы в качестве камуфляжа удерживать губку.
_-_Museo_Civico_di_Storia_Naturale_Giacomo_Doria_-_Genoa,_Italy_-_DSC03233.JPG)
Крабы Dromia personata в аквариуме
Краб Dromia personata с губкой Cliona celata
Dromia personata (лат.) — вид крабов из семейства Dromiidae, обитающий в Северном море, Средиземном море и на северо-востоке Атлантического океана. В некоторых изданиях называется «Волосатый краб». Длина карапакса составляет 53 мм. Обитает, главным образом, вблизи побережий на глубине до 8 м, иногда до 100 м, часто в пещерах. Две последние пары конечностей размещены на спине таким образом, чтобы в качестве камуфляжа удерживать губку.
Крабы Dromia personata в аквариуме
Краб Dromia personata с губкой Cliona celata
