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Jellyfish Warnings

Jellyfish Warning
Collecting Jellyfish Specimens – Images and Material Print E-mail

Photographs: We are constantly looking for good photographs of jellyfish from around South and southern Africa as these provide us with an idea of what species can be found where. If you take photographs of jellyfish and you are willing to let us have a look at them (and so provide you with feedback etc.), please send them on to us either by uploading them through the www site portal (under construction), or by attaching them to an email ( This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ). If you would be willing to share your photographs with others, then we would like to place them on the SAJellyWatch site – suitably accredited of course – and we would be especially keen to have pictures of poorly known species. Don’t forget to let us know when and where the images were taken – this is very important.

Not all images of jellyfish are useful and not all images can be used to identify the species captured on camera, so it is worth remembering a few things before taking any pictures.

  1. Underwater pictures that capture the full animal are better than pictures of beach-cast specimens, but good pictures of undamaged beach-cast animals are still useful.

  2. Several pictures should be taken that capture the whole animal, as well as close-ups of the bell margin and tentacles, as well as the oral arms. The ends of the oral arms are particularly important, as are the number of marginal tentacles so please make sure your photographs convey an idea of both.

  3. If specimens are beach-cast, you may need to re-arrange the specimen so that the above features are visible.

  4. Try and include some index of size in your photographs: an adult person’s hand or a R2.00 coin, for example.

  5. As most jellyfish are transparent – especially around the edge – try and make sure that there is a contrast between the jellyfish and the background, which will allow the jelly’s translucent features to become visible. Perhaps slip a piece of dark material underneath.

  6. Please DO NOT send photographs that have been touched up using (e.g.) Photo-Shop or other software as the natural colours of jellyfish can be very important identification features.

  7. Please do not send “big” photographs in the first instance. When we get back to you with information about your images we may ask you for a bigger picture but please reduce the size of images before you first send them to us.

  8. Is it possible for you to collect the specimen? If so, please read on………


Specimens: Because there are few characters that can be used to separate similar looking species of jellyfish we need material of two different types, ideally from the same specimen. We would like material for genetic analysis and we would like material for morphological examination. If you cannot provide both sorts of material, then we would prefer to have the latter type: i.e. the whole specimen for morphological examination. Below you will find information on how you can fix and preserve the material we require, BUT there are a number of points to remember at the outset.

  1. Not all jellyfish are harmless to humans and so it is important to wear gloves (or put your hands inside plastic bags) when handling the animals.

  2. Even the largest jellyfish are very fragile when you take them out of water so handle them delicately – ideally collect them by scooping them from the water directly and then drain excess water off if necessary. DO NOT collect animals that have been beached as these are usually damaged and will not yield good morphological specimens, unless they appear to be in excellent condition.

  3. Label the samples you collect at the time you collect them (or as soon as possible thereafter) and make sure that the correct label goes with the specimen into the container. Each specimen should have its own label. The labels must include information on the date of collection, the location at which the specimen was collected and the name of the collector: supplementary information on the depth of capture etc is also useful. Labels should be written in pencil or permanent marker and should be written on something that will not disintegrate when immersed in water or preservative (again, a piece of plastic is ideal).


Genetic Material: In order to look at the DNA of a species, we need a small piece (thumb-nail size) of fresh, uncontaminated tissue. This tissue should be cut from the end of an oral arm (NOT Tentacle) and needs to be rinsed a couple of times quite vigorously in clean water (fresh or salt, doesn’t matter) to dislodge foreign matter. Then it needs to be placed into a small jar/tube with excess ethanol: by excess we mean about 10x as much ethanol as tissue. The ethanol MUST be 96% ethanol (by volume) (witblitz is no good as it is only about 40% ethanol), which can be obtained from most good local pharmacies. Don’t forget the label! The tissue specimen then needs to go into the fridge or freezer (it shouldn’t contaminate any foodstuffs, if properly secured) and then the ethanol needs to be replaced twice within the next 24 h. Once you have the specimen, let us know and we will arrange to both collect it and to reimburse you for the material costs involved (so remember to keep your receipt for the ethanol!).

Morphological Material: In order to collect specimens for morphological examination you will need a large bucket with a tightly fitting lid and some formalin. Formalin is an aqueous solution of formaldehyde (also known as methanal NOT methanol) and is a chemical that is used to fix and preserve biological specimens. It can be obtained from most good local pharmacies but when you get it please remember to ask whether you are getting formalin or formaldehyde – the difference is important as formalin is only 40% formaldehyde – though most pharmacies will likely stock formalin. Both chemicals are poisonous carcinogens, and when handling it you need to either wear gloves or put our hands into plastic bags: remember too to wash your hands afterwards. It must also be used in a well ventilated space – outdoors and away from the house is best. Formalin kills pretty much anything so be careful not to spill it on the lawn or in the fish-pond.

Once you have got your jellyfish specimen in a bucket, make sure that there is just enough seawater to cover it completely. Add the label: if you have also collected some genetic material make sure that the labels are the same on both material types and indicate (on both labels) that there is a corresponding “other” sample. This is important as it will help us link the genetics with the morphology. If you have collected more than one specimen of jellyfish and you are trying to put all into one bucket, you can thread the label through the centre of each jellyfish bell using a needle and thread (or equivalent). Okay, with the jellyfish in seawater, it is now time to add the formalin or formaldehyde. You need to add just enough to fix and preserve the sample without going overboard. The final concentration should be in the region of 5% formalin (by volume) [2% formaldehyde], so if your specimen/s plus seawater half-fills a 20 l bucket (equivalent to 10 l), then you need to add about 600 ml of formalin, or 250 ml of formaldehyde (it is better to add more than less). Put the lid on the bucket so that it fits tightly; swirl a couple of times to mix; rinse the bucket off with water and store in a dark, well ventilated space – ideally outside and away from the house or garage. Once you have the specimen, let us know and we will arrange to both collect it and to reimburse you for the material costs involved (so remember to keep your receipts for buckets and formalin).

If you regularly see jellyfish and think that you will be in a position to collect regular samples for us, we can arrange to send you a “collecting kit”. Further details can be sought by contacting us: either via the www site or by email ( This e-mail address is being protected from spam bots, you need JavaScript enabled to view it )