THE BLUE DRAGON

Drop-Dead Gor­geous

Scuba Diver Australasia - - Contents -

Beau­ti­ful but deadly, Glau­cus at­lanti­cus, com­monly known as the blue dragon, is not what one would ex­pect of a mere slug. Not only is it vis­ually stun­ning; it pos­sesses abil­i­ties un­like any other crea­ture on Earth.

AP­PEAR­ANCE: The blue dragon has three pairs of arms, each one shorter than the last as they go fur­ther down its body. On these arms are sin­gle rows of ten­drils called cer­ata which hold sting­ing cells – there can be up to 84 of these on a sin­gle in­di­vid­ual. The dor­sal side is a sil­very grey colour while the ven­tral side is a light blue. Its feet on the dor­sal side have dark blue stripes. The jagged teeth of this gas­tro­pod mol­lusc help it to scrape food par­ti­cles and draw them into its mouth

OTHER NAMES: Sea swal­low, blue an­gel, blue glau­cus, blue dragon, blue sea slug, blue ocean slug 1

Though part of the

nudi­branch fam­ily, the blue dragon is very dif­fer­ent from your av­er­age sea slug, and is known to be pelagic, us­ing the ocean cur­rents to carry it along

2

The blue dragon

floats up­side down for cam­ou­flage: Its blue side faces up­wards to blend with the blue wa­ter, while the down­wards fac­ing sil­ver side blends in with the ocean’s sur­face 5 All blue dragons are

hermaphrodites, mean­ing they have both male and fe­male re­pro­duc­tive or­gans

3

It only feeds on ven­omous

crea­tures, of­ten much larger than it­self, such as the Por­tuguese man o’ war and can de­liver a pow­er­ful

sting to paral­yse its prey

4

The im­mune sys­tem of a blue dragon is built to

re­sist the venom of its prey 6 When two blue dragons mate, they both

pro­duce egg strings. These egg strings lack a hard sub­strate to at­tach to, and are of­ten left to float freely in the wa­ter or are placed on the re­mains of their prey un­til the lar­vae hatch

7

These little slugs have the amaz­ing abil­ity to swal­low the ne­ma­to­cysts of its ven­omous prey. These ven­omous cells are stored in the ex­trem­i­ties of their cer­ata, mak­ing the blue dragon’s sting pack an even more pow­er­ful punch

Dur­ing mat­ing, both fe­male re­pro­duc­tive or­gans will re­lease an egg string con­tain­ing about 20 eggs

cen­time­tres long

The male re­pro­duc­tive or­gan is es­pe­cially large and hooked

Ne­ma­to­cyst in­side cell Dis­charged ne­ma­to­cyst

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