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WonderAnimal defence fact

When attacked, hagfish release mucus and microscopic protein threads that expand through seawater into extraordinary volumes of defensive slime.

Hagfish

OceanBiologyEvolutionScience

The story behind the card

Hagfish are eel-shaped, jawless fish that live on the seafloor. More than 70 species are known, and fossils about 300 million years old already look much like them. They often feed by burrowing into the carcasses of dead fish and whales. Their slime comes from glands along the body, which release mucus and tightly coiled protein threads. In seawater the threads unravel in a fraction of a second, and a small amount of secretion can turn litres of water into slime, enough to clog the gills of an attacking fish; underwater cameras have filmed sharks letting go and swimming off. Each thread is far thinner than a human hair yet strong and stretchy, so researchers study it as a model for new fibres. Afterwards the hagfish ties itself in a knot and slides the knot along its body to wipe the slime off.

Türkçe oku
Miksinler saldırıya uğradığında mukus ve mikroskobik protein iplikleri salar. Bunlar deniz suyunda açılarak kısa sürede büyük miktarda koruyucu balçığa dönüşür.

Miksinler, deniz tabanında yaşayan, yılan balığına benzeyen çenesiz balıklardır. 70'ten fazla türü bilinir; yaklaşık 300 milyon yıllık fosiller bile bugünküleri andırır. Çoğu zaman ölü balıkların ve balina leşlerinin içine girerek beslenirler. Balçık, vücut boyunca dizili bezlerden salınan mukus ve sımsıkı sarılmış protein ipliklerinden oluşur. Deniz suyuna karışınca iplikler saniyenin küçük bir kesrinde çözülür; azıcık bir salgı litrelerce suyu balçığa çevirir ve saldıran balığın solungaçlarını tıkayabilir. Su altı kameraları, miksini bırakıp uzaklaşan köpekbalıklarını görüntülemiştir. Her iplik insan saçından çok daha incedir ama sağlam ve esnektir; araştırmacılar bu yüzden onu yeni lifler için örnek alıyor. Tehlike geçince miksin kendine düğüm atar ve düğümü gövdesi boyunca kaydırarak balçığı sıyırır.

Sources and further reading

Background reading: Hagfish
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