Ushaka

Oshaka, yiqembu lezinhlanzi elasmobranchii cartilaginous eziphawuleka nge-endoskeleton engenamambo. Ama-dermal denticles, izimbobo ezinhlanu kuya kweziyisikhombisa ezinhlangothini zombili kanye namaphiko esifuba angahlangani Ikhanda. Oshaka banamuhla bahlukaniswe ngaphakathi kwesigaba USelachii futhi bayingxenye yeBatamorphi imisebe ne-skates. Eminye imithombo yandisa igama elithi shark njengesigaba esingahleliwe esihlanganisa amalungu aphelile e-Chondrichthyes. Inhlanzi enesiqu esiqinile enesimo esifana nesoshaka, njenge-hybodonts. Ama-chondrichthyans afana noshaka afana ne-Icladoselache ne-Doliodus avele okokuqala ngenkathi ye-Devonian. Iminyaka eyizigidi ezingu-419 kuya kwezi 359, yize amanye ama-chond Richthyan anezinsalela amadala njenge-Late Ordovician iminyaka eyizigidi ezingu 458 kuya kwezi 444 edlule. Oshaka besimanje bokuqala abaqinisekisiwe (i-Selachii) yaziwa kusukela ku-Early Jurassic eminyakeni eyizigidi ezingu-200 edlule, nelungu elidala kunawo wonke elaziwayo nge Agaleus, yize amarekhodi oshaka beqiniso engase abuyele emuva kuze kufike ku(-I-Permian).

Oshaka bahlukana ngobukhulu kusuka kwi dwarf lanternshark encane (I-Etmopterus perryi), uhlobo olwandle olujulile olungamamitha awu-17 kuphela (6.7 ubude, kuya ku-whale shark (I-Rhincodon typus), inhlanzi enkulu kunazo zonke emhlabeni, efika cishe kumamitha angu-12 (40 kuya kumamitha awu-18.8 (62 ubude. Zitholakala kulo lonke ulwandle futhi zivamile ekujuleni okufinyelela kumamitha angu-2,000 (6,600 . Ngokuvamile azihlali emanzini ahlanzekile, yize kunezingxenye ezimbalwa ezaziwayo, njengoshaka we-bull kanye noshaka basemfuleni, abangatholakala kokubili emanzini olwandle nasemanzini ahlanzayo, kanye noshaka we-Ganges, ohlala emanzini ahlobile kuphela. Oshaka banesembozo sama-placoid scales (amazinyo) esivikela isikhumba ekulimaleni nasemazilwaneni ngaphezu kokuthuthukisa uketshezi lwabo. Zinezinhlobo eziningi zamazinyo angashintshwa.