Muoi loai ran ky la nhat the gioi

Thứ bảy, 09 Tháng hai 2013, 05:09 GMT+7

Co khoang 3.000 loai ran tren the gioi, bat dau xuat hien vao thoi ky cua nhung ga khung long khong lo. Chung da thich nghi voi moi truong de hinh thanh mot nhom dong vat ky quai khac thuong ma dien hinh la 10 loai ran duoi day.

10. Ran voi voi (Elephant trunk snake)

Muoi loai ran ky la nhat the gioi

Loai ran la nay duoc tim thay chu yeu o Indonesia, mac du mot so ho hang cua chung lai dinh cu ben Uc. Cai ten xuat phat tu bo da nhan nheo va rong thung thinh, co ve qua lon doi voi chung. Vay cua chung cung khac thuong: lon va co buou. Vi the chung con duoc goi bang cai ten khac la “ran mun com”.

Ran voi voi dai chung 2,5 met, toan song duoi nuoc ma chang bao gio bo len dat lien vi thieu nhung vay lon o bung nhu cac loai ran khac de co the di chuyen tren mat dat. Chung an luon va nhung loai ca da tron. Khong co noc doc, chung giet chet con moi bang cach lay than khoe va xu xi nhung buou cuon lay de giu chat con moi va siet chat cho den chet.

9. Ran rau (Tentacled snake)

Muoi loai ran ky la nhat the gioi

Mot loai ran nuoc khac o Dong Nam A goi la “ran rau” co hai cai “rau” bang thit o hai ben mep. Hai chiec rau nay co do nhay cam cao, cho phep chung phat hien moi su chuyen dong trong nuoc va lao thang vao bat ky con ca xau so nao boi gan do.

Dieu thu vi la toc do tan cong cua chung cuc nhanh va bat gon con ca kia chi trong 15 mili giay. The nhung phan xa tuyet voi va cuoc tan cong chop nhoang ay doi khi van khong du de bat ca nen ran rau con co mot thu thuat thong minh khac nua de buoc con moi phai boi theo huong nguy hiem. Khi thay mot con ca den gan, ran lay than lam phat ra mot tieng quay rat nho khien ca tuong co moi, boi den va roi ngay truoc mieng ran.

Trong so tat ca cac loai ran, chung la loai duy nhat luong truoc nhung phan ung cua con moi de hanh dong cho phu hop. Mac du ran rau co noc doc nhung khong lam hai nguoi. Chung chi dai 90cm. Cung giong nhu ran voi voi, chung toan song duoi nuoc nhung cung co the bo len can.

8. Ran mui dai (Long nosed vine snake)

Muoi loai ran ky la nhat the gioi

Cung la mot loai co nguon goc Dong Nam A, ran mui dai la mot loai an thit song tren cay. Tuy nhien, khong giong nhung con ran khac, mat chung cuc tinh, cho phep chung tan cong con moi voi do chinh xac tuyet voi. Doi mat cua chung cung khac thuong trong tua nhu mot lo khoa, dong tu nam ngang.

Nho mau sac hoa lan duoc vao dam la cay (ke ca chiec luoi cung xanh la cay), nen ca con moi lan cac loai san moi deu kho phat hien ra chung. Chung rat nhe nen di chuyen nhanh chong qua cac tan la, tham chi chi mot nua than bam vao cay chung cung khong roi! Chung an chu yeu than lan va ech nhai, va mac du co noc doc, chung khong de doa nghiem trong doi voi con nguoi. Khi bi chung can chi hoi dau trong vai ngay.

7. Ran mui la (Langaha nasuta)

Muoi loai ran ky la nhat the gioi

Day co le la mot trong nhung loai bo sat ky la nhat the gioi. Cung giong nhu ran mui dai, loai ran mui la nho hinh dang dac biet ma thich nghi duoc voi loi song tren cay. Thuc an chu yeu cua chung la than lan.

Dac diem ky la la tren mui cua chung co mot “do trang suc” quai di giong nhu mot chiec nhanh la dua nhon hoat, nhung o ran duc va ran cai chiec “la” nay khac nhau. Da ran duc co mau vang va nhan, mui la nhon trong khi ran cai co vay nau va xu xi, mui la phang, co rang cua. Dieu rat it khi gap la thoat nhin co the biet ngay gioi tinh cua chung. Ran mui la chi song o Madagascar va dang dung truoc nguy co tuyet chung. Chung co noc doc, vet can rat dau nhung khong nguy hiem den tinh mang.

6. Ran vay gai (Atheris hispida)

Muoi loai ran ky la nhat the gioi

Song trong nhung khu rung mua cua Trung Phi, ran vay gai nho nhung rat doc duoc chu y boi doi mat lon va nhung chiec vay nhon tren than xep de len nhau nhu lop ngoi, trong giong nhu long (nen nguoi ta con goi la ran co long nhung that ra khong phai).

Ran vay gai chi dai 75 cm, con duc lon hon con cai (dieu bat thuong o cac loai ran). Chung co rang nanh dai nhung quap vao trong nhu da so ran. Noc cua chung lam mau khong dong, rat doc nhung da co thuoc giai doc. Vet can dau, sung, thuong gay tu vong neu khong cap cuu kip thoi. May la chung cuc hiem va song xa nguoi.

5. Ran sung (Horned viper)

Muoi loai ran ky la nhat the gioi

Song trong sa mac Bac Phi va Trung Dong, ran sung kich thuoc nho, khong qua 50cm. Chung thuong co mot cap sung phia tren mat, nhung cung co mot so con hoan toan khong co nen rat de nham voi cac loai khac.

Ran sung co noc doc nhung khong du manh de gay tu vong cho nguoi. Khi doi mat voi nguy hiem chung cuon minh lai co vao nhau tao ra am thanh de de doa.

Lan dau gap loai ran nay vao nam 1768, nha tu nhien hoc Ao Nicolaus Laurenti goi chung la “ran luc Ai Cap”, mot con ran than lon trong than thoai Hy Lap, tron duoi cat trong sa mac, tan cong bat cu con vat nao di qua bang cach dung cap sung de me hoac. Co the chinh no la nguyen mau de dan gian xay dung nen than thoai vi trong thuc te, ran sung hanh dong dung nhu vay: chui duoi cat, chi tho sung len va dot ngot xuat hien bat cac con vat khac (thuong la con trung) bo den gan. Chi co dieu la than thoai phong dai kich thuoc, tri tue va su nguy hiem cua chung len ma thoi. Cho den nay, nguoi ta van chua giai thich duoc chung dung sung lam gi (chac chan khong de lam moi) va vi sao con co, con khong.

4. Ran hang (Burrowing asp)

Muoi loai ran ky la nhat the gioi

Ran hang co the xem nhu mot loai ran la, kich thuoc nho, chi gap o chau Phi. Gan nhu suot doi chung song duoi long dat, khong ra khoi chiec hang bi mat, ngoat ngoeo cua chung.

Ran hang (con goi la ran rang kiem) chuyen san cac loai gam nham nho nhung chiec rang nanh dai, hinh luoi kiem, tho ra rat nhanh khi can de tiem noc doc. Chung lam chet con moi ma khong can mo mieng.

Rang nanh cua ran hang rat linh hoat, chuyen dong doc lap voi nhau de giet va dua con moi vao mieng. Luong chat doc cua mot vet can khong du de lam chet mot nguoi truong thanh. Tuy nhien, noc doc cua ran hang ngoai tac dong vao than kinh gay dau don, con gay hoai tu (rang nanh dai nen ngap sau trong cac co) vi the nguoi ta rat so loai ran nay, tuy it gap.

3. Ran ho keelback (Tiger keelback)

Muoi loai ran ky la nhat the gioi

Day la mot loai ran nuoc, con goi la yamakagashi hay ran nuoc Nhat Ban, song pho bien o vung Dong Nam A. Chung nho, it khi dai qua 1m va rat nhut nhat, thuc an chu yeu la ech va coc.

Ran ho keelback duoc coi la vo hai trong mot thoi gian dai, cho den khi mot so nguoi bi chung can chet vao nhung nam 80 the ky truoc. Dua vao nghien cuu trong phong thi nghiem, cac nha dong vat hoc phat hien ra mot dieu thu vi: Khong phai tat ca ran ho keelback deu co noc doc ma chi o nhung noi co nhieu coc moi co.

Mat khac, du ran bo me co chat doc thi ran con cung khong he co. Thi ra, chat doc do khong do ran tu san xuat ma “chiem doat” cua coc, “de danh” chat doc thu duoc (goi la cac chat bufadienolides) vao mot tuyen duoi co de lam vu khi cho minh trong viec tu ve va san bat cac con moi. The nhung chung con biet cach xu ly de chat nay doc hon han chat ma chung chiem huu duoc. Su khon ngoan ay khien chung tiet kiem duoc cong suc hon khi bat moi va tu ve truoc ke thu co hieu qua hon so voi dong loai song o nhung noi khac.

2. Ran bay (Flying snake)

Muoi loai ran ky la nhat the gioi

Ran bay duoc tim thay trong rung mua nhiet doi tai An Do va Dong Nam A. Mac du co ten nhu vay nhung chung khong thuc su bay ma chi lieng.

Khi ran bay muon di chuyen tu cay nay sang cay khac, chung lao vao khong khi, dong thoi xoe cac de xuong suon, roi co len phia da day, khien than no det ra va tro thanh mot canh gia hoi lom, hop voi dang cua khi dong hoc.

Ran bay lieng con gioi hon ca soc bay. Trong khi soc co the lieng duoc 60 met tren khong, thi khoang cach do cua ran bay len toi 100 met hoac hon nua. Chung dinh huong tot hon va kiem soat duong bay gioi hon han so voi soc bay. Ran bay co noc doc, nhung khong gay nguy hiem cho con nguoi. Chung an chu yeu la than lan va cac loai dong vat nho khac, va phan lon thoi gian chung o tren cay.

1. Ran bien (Sea snake)

Muoi loai ran ky la nhat the gioi

Ran bien ky la nhat trong so cac loai ran. Chung cung ho voi ran ho mang va ran san ho (Elapidae), nhung da thich nghi voi mot cuoc song giua bien khoi.

Hien da tim 62 loai o Thai Binh Duong va An Do Duong. Chung cuc doc, mot so loai nhu con ran bien co mo, noc doc manh gap muoi lan so voi ran ho mang. Mot loai ran bien, goi la ran Belcher, duoc xem la doc nhat trong tat ca ho nha ran tren bien va tren dat lien.

That may la ran bien thuong hien lanh va rat it nguoi chet vi chung. Hau het cac loai ran bien khong can phai quay tro lai cac bai bien de de trung nhu rua bien (tru mot vai loai). Chiec vay lon o bung ma ran tren can dung de di chuyen, do thich nghi lau doi da bien mat nen ran bien khong the len bo duoc nua. Tham chi chung con co kha nang tho truc tiep voi oxy hoa tan trong nuoc thong qua da. Chung co cac tuyen dac biet tren luoi, de loai tru muoi ra khoi co the moi khi danh luoi.

Bao Chau (Theo Listverse.com)

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