Impossibly Beautiful Marine Life in Sydney Harbour – Part 3

Impossibly Beautiful Sea Life of Sydney Harbour – Part 1

As promised, here are more amazing creatures both big and small who call Sydney Harbour home. Although if you are planning on a snorkelling or diving expedition, be aware that most of these creatures will be elusive, shy and unwilling to interact with you.


Seahorses are gorgeous, mystical and delicate creatures. They have captivated the imagination of children and adults for time immemorial. They seem to be so shy when they are viewed up close seem to scurry away as though coy and shy. They are a delight to behold when snorkelling or diving. Sydney Harbour is full of them!

As one of the most famous animals in the sea, they are instantly recognisable. They have a body protected by bony plates that are arranged in rings along with a long tubular snout that gives them an equine appearance, hence the name. They are slow moving and graceful and don’t have large fins. Seahorses tend to float around rather than swim and have a long tail akin to a possum’s tail. They use this to wrap themselves around seaweed and coral in order to cling to it and be camouflaged.

Impossibly Beautiful Sea Life of Sydney Harbour – Part 1

As they don’t swim fast, their main defence mechanism is hiding and blending into their surrounds. Just like Weedy Seadragons they consume food through their long snouts and eat mostly small crustaceans like shrimps and crabs.

They are flirtacious and surprisingly sexual creatures. They produce large broods of eggs in the season, usually beginning in early spring. Many species of seahorses form pairs for the season and the males follow the females around and stay close to them. Sounds just like a typical night out in Sydney CBD really.

The female deposits eggs into the male’s pouch using her ovipositor. After this, the male looks after the eggs for 3-4 weeks before giving birth to the young. It’s a fascinating reversal of roles when compared to many other creatures. The male gives birth to a whole lot of baby seahorses who float away and start their own little lives. It’s quite a magnificent thing to behold. The father then shows his empty pouch to the females and one of them will deposit another batch of eggs in there shortly afterwards.

Seahorses like Weedy Seadragons have protected status in Australia. Their habitat is under threat by the actions of humans. Sometimes they are taken for the illegal aquarium trade and used illegally in Asian medicines. Dragon Search are an Australian foundation that make sure no Australian species of seahorses are being sold illegally in Asian medicine or the aquarium trade.

 Impossibly Beautiful Marine Life in Sydney Harbour – Part 3
Seahorse found near Bare Island, Sydney

Australian Fur Seal

The Australian Fur Seal Arctocephalus pusillus doriferus is the largest of all the fur seals, weighing around 200 – 300kg. They have a strong and robust body covered in thick brown hair all over except their flippers. They have a broad head and long backwards sweeping whiskers, they are all round impressive to behold, some would even say incredibly handsome.

They have a set of sharp carnivorous teeth that are akin to canine teeth. As with other members of the family Family Otariidae (sea lions and seals) they have the ability to move around on land/ However their movements are cumbersome on their front flippers. They save all of their ballet-like grace for under the water, where their twirls and girations are legendary.

They tend to be distributed in the islands of Bass Strait, Tasmania, southern Victoria and remote parts of the NSW coast. Their numbers are secure yet they are commercially hunted in South Africa. Despite their protected status in Australia their numbers are half that of historic pre-sealing times. This could be due to increased competition with commercial fishing operations.

Australian Fur Seals feed on bony fish along with squid and octopus. They are daring hunters and sadly will get entangled in fishing nets if it means a chance at getting at the fish.

Each year they come ashore and establish breeding colonies. There is always an aggressive alpha male who defends his territory and rights to the females, against the encroachment of other males who come ashore to fight him. The females spend most of the time at sea when pregnant, only coming ashore to give birth to a single pup before taking off to feed again. As a result there is a high infant mortality rate during this time. The mum may give birth to several pups in a season and they can stay weaning with mum for more than six months.

 Impossibly Beautiful Marine Life in Sydney Harbour – Part 3
Australian fur seals

Got a favourite sea creature from Sydney Harbour that I’ve missed? Let me know and I’ll talk about it next time!

Stay tuned for part four coming up next week.

Find out more…

Abyss Sydney Marine Life

Fishes of Sydney Harbour

Unseen Nature Art from Australia’s First Fleet

What Montaigne Can Teach Us About Deep Sea Aliens

Five Creepy Islands in Sydney Harbour

Published by Content Catnip

Content Catnip is a quirky internet wunderkammer written by an Intergalactic Space Māori named Content Catnip. Join me as I meander through the quirky and curious aspects of history, indigenous spirituality, the natural world, animals, art, storytelling, books, philosophy, travel, Māori culture and loads more.

2 thoughts on “Impossibly Beautiful Marine Life in Sydney Harbour – Part 3

  1. Beautiful images, I saw a documentary which talked about the sexuality of sea horses, and apparently male sea horses are the ones who carry the eggs in a womb-like sac until they are born.


    1. I know, it’s so interesting that the male is the nurturing one, it’s not just the female or both. They are so magical. Each creature has secrets and wisdom to impart to us when we learn about its biological features, evolutionary adaptations and behaviour 🙂 Here is a great book that you may like, it unlocks these fascinating things, it’s called The Book of Barely Imagined Beings: A Modern Bestiary,


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