Crabs yog ib pawg ntawm cov crustaceans uas yog tus txiav txim Decapoda. Qhov kev txiav txim no suav nrog qee 15,000 hom, suav nrog prawns thiab prawns.
Crabs yog ib feem tseem ceeb ntawm lawv cov ecosystems, ob qho tib si vim lawv yog cov neeg siv khoom zoo thiab vim lawv yog cov nyiam nyiam cov tsiaj nyeg ntawm ntau cov tsiaj hauv dej. Tsis tas li ntawd, raws li peb yuav pom, qee qhov tseem ceeb rau kev rov ua dua ntawm cov organic. Tab sis noj tau dab tsi? Peb qhia koj txog nws hauv tsab xov xwm no ntawm peb lub xaib.
Kab Cab
Cov no yog cov yam ntxwv tseem ceeb ntawm crabs:
- Tagmas: Nws lub cev muab faib ua cephalothorax, uas suav nrog lub taub hau thiab ib feem ntawm lub thorax, thiab pleon, uas yog dab tsi. feem ntau yog hu ua "tail". Txawm li cas los xij, qhov kawg tuaj yeem txo qis heev.
- Exoskeleton: Crabs yog cov tsiaj uas muaj exoskeletons. Nws yog ib lub pob txha sab nraud ua los ntawm chitin. Tsis tas li ntawd, nws tuaj yeem muaj calcium carbonate thiab ua kom tawv tawv heev, ua ib hom plhaub.
- Muda: Nrog kev loj hlob, lub exoskeleton "outgrows lawv". Vim li no, zoo li lwm cov arthropods, lawv tshem tawm ntawm nws thiab tsim ib qho tshiab.
- Legs: zoo li tag nrho cov decapods, crabs muaj 10 khub cegHauv cephalothorax lawv nthuav tawm 5 khub. Thawj tus siv lawv hauv kev pub noj thiab lwm tus yog locomotors, uas yog, lawv siv lawv taug kev. Hauv pleon lawv muaj 5 khub ob txhais ceg uas lawv siv ua luam dej.
- Claws: Feem ntau, cov tsiaj no muaj ob txhais ceg tig los ua claws. Cov no muaj kev tiv thaiv thiab khoom noj muaj nuj nqi. Lawv feem ntau me dua rau cov poj niam.
- Integumentary gas exchange: crabs muaj gills txuam nrog lub hauv paus ntawm lawv ob txhais ceg, tab sis lawv muaj kev tiv thaiv los ntawm exoskeleton.
- Gastric mill: yog lub plab pob txha. Cov no yog cov qauv uas zom thiab zom zaub mov. Ntawm cov yam ntxwv ntawm crabs, qhov no yog qhov tseem ceeb tshaj plaws rau kev nkag siab txog lawv cov zaub mov.
- Senses: Crabs have sessile compound eyes or eyes on a mobile stalk. Lawv kuj muaj cov rhiab appendages thiab ob khub ntawm cov kav hlau txais xov, ua tsaug rau qhov lawv pom lawv ib puag ncig.
- Oviparous reproduction: Cov tsiaj no yug los ntawm nteg qe. Cov poj niam thauj thiab incubates mus txog thaum lawv loj hlob.
- Indirect development: ib tug larva hu ua "nauplius" hatches los ntawm lub qe thiab muaj ib tug planktonic lub neej. Tus larva no dhau los ua tus txheej txheem metamorphosis mus txog thaum nws dhau los ua neeg laus peb txhua tus paub.
- Benthic habitat: Muaj qee qhov tshwj xeeb, cov crabs nyob hauv dej los yog hauv qab hiav txwv. Qhov no tuaj yeem ua rau peb paub txog dab tsi crabs noj.
Crayfish noj dab tsi?
Peb hu cov tsev neeg Astacidae, Parastacidae thiab Cambaridae crayfish. Cov crustaceans no nyob hauv qab ntawm cov dej ntws thiab lwm lub cev dej tshiab, qhov chaw lawv nkaum ntawm cov tsiaj txhu xws li mustelids.
Crayfish pub suav nrog txhua yam ntawm cov organic teeb meem tam sim no nyob rau hauv txaj Lawv yog omnivorous tsiaj thiab noj algae, me me invertebrates, ntses thiab txawm carrion. Yog li ntawd, lawv tseem ceeb heev rau kev rov ua dua tshiab ntawm cov neeg tuag uas tuag saum txaj, zam lawv cov tsub zuj zuj.
Piv txwv quas crayfish
Nov yog ib co piv txwv ntawm crayfish:
- European crayfish (Austropotamobius pallipes)
- American Red Crab (Procambarus clarkii)
Cab noj dab tsi?
Crabs yog ib pab neeg coob coob ntawm cov crustaceans. Nyob rau hauv nws peb tuaj yeem pom ntau hom crabs, xws li hermits (Paguroidea), spiny lobsters (Palinuridae) thiab feem ntau brachyurans (Brachyura)..
Teb lus teb rau qhov sea crabs noj tsis yooj yim, vim kev noj ntawm cov tsiaj no nyob ntawm hom, nws nyob thiab nws txoj kev ua neej. Vim li no, peb thiaj yuav faib cov ntses hiav txwv ua ntau hom raws li lawv cov zaub mov:
- Herbivorous crayfish
- Omnivorous crayfish
Cov nqaij nyuj yog ib txwm benthic. Yog li ntawd, noj cov tsiaj uas nyob ntawm ntug dej hiav txwv, xws li cov crustaceans me thiab molluscs. Txawm li cas los xij, nws muaj tseeb tias qee qhov, qee zaus, tuaj yeem noj algae.
Ntawm no yog ib co piv txwv ntawm carnivorous crabs:
- Crab (Cancer pagurus)
- Blue daus roob ris (Chionoecetes opilio)
Herbivorous crayfish
Cov tsiaj txhu marine noj tsuas yog nplooj thiab tua ntawm cov nroj tsuag, ob qho tib si marine thiab ntug hiav txwv dej. Cov no muaj xws li algae, seagrasses thiab mangroves. Txawm li cas los xij, txhawm rau ntxiv lawv cov zaub mov lawv yuav noj cov me me invertebrates hauv qhov tsawg heev.
Ib qho piv txwv ntawm herbivorous sea crab yog mangrove crab (Aratus pisonii). Nws yog arboreal roob ris, uas yog vim li cas qee tus kws sau ntawv xav tias nws yog ib nrab av.
Omnivorous crayfish
omnivorous crabs muaj ntau yam kev noj haus, uas tso cai rau lawv hloov tau zoo heev rau cov ecosystems sib txawv. Ntawm cov zaub mov ntawm cov crabs uas yog pab pawg no peb tuaj yeem pom me me invertebrates, algae thiab txawm carrion.
Qee yam piv txwv ntawm omnivorous sea crabs yog:
- Blue crab (Callinectes sapidus)
- txiv maj phaub (Birgus latro)
av crabs noj dab tsi?
av crabs yog cov uas siv lawv lub neej ntau dhau ntawm dej. Txawm li cas los xij, lawv cov larvae yog cov dej thiab cov poj niam rov qab mus rau hauv hiav txwv kom yug me nyuam. Lawv kuj yuav tsum tau nyob hauv qhov chaw ntub dej kom lawv cov gills hydrated.
av crabs feem ntau yog cov tsiaj txhu. Koj cov zaub mov yog raws cov txiv hmab txiv ntoo thiab nplooj. Txawm li cas los xij, lawv feem ntau pub rau carrion thiab me me invertebrates thiab.
Piv txwv av crabs
Ntawm no yog ib co piv txwv ntawm av crabs:
- Red av crab (Gecarcinus lateralis)
- Blue land crab (Cardisoma guanhumi)
Aquarium crabs noj dab tsi?
Crabs yog cov tsiaj uas yuav tsum tau nyob ywj pheej thiab nyob rau hauv lawv cov ecosystem, tsis nyob rau hauv lub thoob dej yug ntses. Txawm li cas los xij, rau ntau yam laj thawj, qee zaum peb raug yuam kom saib xyuas tus roob ris uas peb tsis tuaj yeem rov qab los tsev. Yog tias qhov no yog koj li thiab koj xav paub dab tsi lub thoob dej yug ntses noj, peb yuav muab qee qhov qhia rau koj.
Cov khoom noj khoom haus ntawm cov thoob dej yug ntses yog nyob ntawm lawv qhov chaw nyob, kev ua neej thiab hom. Qhov zoo tshaj plaws yog kom Tau txais cov ntaub ntawv zoo heev txog koj cov zaub mov zoo thiab sim ua raws liTsuas yog ua li no peb yuav lav koj cov khoom noj kom raug. Yog tias tseem muaj kev xav tsis thoob, nws tseem ceeb heev uas yuav tsum tau mus ntsib tus kws tshaj lij uas tuaj yeem qhia peb.
Piv txwv aquarium crabs
Qee yam piv txwv ntawm crabs dav siv hauv thoob dej yug ntses yog:
- European Fiddler Crab (Uca tangeri): This is a semi-terrestrial crustacean. Nws yog omnivorous thiab pub tsuas yog ntawm cov khoom noj nplua nuj, xws li microalgae. Cov nroj tsuag Marsh, litter thiab carrion tuaj yeem pom hauv lawv cov zaub mov.
- Red av crab (Neosarmatium meinerti): nws yog ib lub pas dej ntsev, arboreal nyob rau theem neeg laus. yog nws pub, tshaj txhua yam, ntawm mangrove nplooj thiab tua. Nws kuj tseem tuaj yeem noj cov nplooj khib nyiab, algae thiab me me invertebrates.
- Zaj sawv roob ris (Cardisoma armatum): yog ib lub roob roob ris uas feem ntau pub rau nplooj, txiv hmab txiv ntoo, paj, kab thiab lwm yam kab.
- Panther crab (Parahelphusa pantherina) : it is a freshwater crustacean and, so, a generalist omnivore.
