SEA SPIDERS

At Dalton Koss HQ we can already hear the arachnophobes fearfully exclaiming, “Sea Spiders! Will they bite me if I go for a swim? Are they poisonous?”

The answer to both questions is no. Sea Spiders are not interested in devouring humans.

Sea Spiders are scientifically known as pycnogonids. You can see in the image below, that sea spiders are not as chunky looking as their land dwelling cousins and are quite small in size (the Sea Spider in this image was no bigger than a $1 Australian coin).

This sea spider's scientific name is Pseudopallene ambigua and was found moving around a subtidal rocky reef inside Port Phillip Heads Marine National Parks, Victoria, Australia.
This sea spider’s scientific name is Pseudopallene ambigua and was found moving around a subtidal rocky reef inside Port Phillip Heads Marine National Parks, Victoria, Australia. The arrows point to several interesting body features.

This is because Sea Spiders have developed a number of really interesting body features over a long period of time. Here are just a few interesting feature facts:

Fact 1: The abdomen of the sea spider is very small and located towards the back of the body, while some of the gut is located in its legs. Their waste products are released directly into the seawater via a diffusion process across their cell walls.

Fact 2: Sea spiders use the same cell wall diffusion process to obtain oxygen, i.e. they have no lungs or respiratory system to breathe oxygen like many other animals.

Fact 3: Due to their very small body size, the sea spider’s reproductive system is found in their legs.

Fact 4: Female sea spiders deposit their fertilised eggs, which are then picked up and looked after by the male sea spider.

Fact 5: Most sea spider legs end in very small claws.

Fact 6: At each growth stage, starting from the larval phase, the sea spider develops a new set of legs until it reaches adulthood.

Fact 7. Sea spiders have a proboscis (think of it as their mouth and tongue rolled into one) so that they can suck out the fluids of animals they eat, for example, anemones, hydroids and bryozoans, but NOT humans.

Fact 8: Sea Spiders live in cool and warm water oceans at all depths.

How can I spot a Sea Spider?

Dalton Koss HQ’s tip for spotting a sea spider is to use a snorkel and mask and slowly drift over rocky reefs at high tide (for safety, always snorkel with a buddy). Sea Spiders are quite small so you need to look closely between seaweed tufts, anemones and other hydroids that grow on the rock.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s