Marine Science 2016 Edition

Marine Invertebrates (1) Page 279 Class Hydrozoa Bluebottle Blue bottles form colonies of specialised individual cells as shown in Figure 279.1 and are often confused as jellyfish. Each group of cells performs a different function: feeding, digestion of food, reproduction. Even the float is a group of cells designed for floating. The bluebottle gets its name from the colour and shape of its body which looks like a blue, sail-shaped balloon up to 25 cm long. The trailing tentacles are up to 10 m long (over 30 feet), which makes them hard to avoid especially in strong currents or large waves. Although not fatal in most cases, the sting causes severe pain and welts on the skin. Vinegar should not be used on blue bottle stings as it increases irritation - use only cold water and ice to relieve the pain. Other hydrozoans include the fireweed and stinging hydroids. Class Cubozoa Box jellyfish Box jellyfish, also known as sea wasps, are the deadliest stinging jellyfish in the world and have killed swimmers, adults and children, off northern Australian beaches. They have large, transparent, bell- shaped bodies up to 30 cm across, each with a large, trailing clump of tentacles up to 4 m long, containing millions of nematocysts. Preferring warmer waters, they are found only in the tropical waters of Australia’s far northern beaches between December and March. Beaches from Cairns around to Broome are closed for swimming during this period. Victims, especially children, usually die within minutes of being stung after suffering intense pain followed by paralysis (caused by the poison shocking the heart) followed by breathing failure. The poison also attacks the red blood cells in the victim’s skin upon contact and produces large, purple, whip-like marks. Irukandji These are small members of the box jellyfish family with a bell size of about 2 cm. This means they can pass through stinger nets. Although the sting is very minor the pain which develops later can be excruciating. If stung in Northern Australia, flood the area with vinegar and get to hospital within 20 minutes for pain killers. Swimming tentacles Reproductive tentacles Feeding tentacles Figure 279.1 Different colonies of the blue bottle (Illustration Bob Moffatt) Figure 279.2 Blue bottle (Photo Neville Coleman) Figure 279.3 Box jellyfish (Photo Neville Coleman) Figure 279.4 Irukandji (Photo Jamie Seymour) Treatment for box jellyfish and Irukandji 1. Flood the area stung with vinegar. 2. Seek medical assistance as fast as you can. 2 cm Fireweed Web: Search engine word — Irukandji http://www.reef.crc.org.au/aboutreef/coastal/irukandji.html http://cnsfse01.jcu.edu.au/schools/tropbio/cubozoan.html