Greater Argonaut

We were swimming in the sea not so far from our house, when Aya shouted that she’d found a weird shell floating in the water. At first we thought it was a plastic toy but it seemed to be natural, although it was unlike any shell I’d ever seen. After going home, we looked in our sealife book and found out that it was the egg-case of a Greater Argonaut, which is a kind of octopus. The female produces this papery egg-case, which makes it look like a nautilus. There’s an interesting Wikipedia article about it: here.

I think this is probably one of the most beautiful objects, natural or artificial, I’ve ever seen.

Argonauta argoArgonauta argoArgonauta argo

Mollusca: Cephalopoda: Octopoda: Argonautidae
Argonauta argo
Greater Argonaut = aoigai

Location: Beach near Kanezaki (Google map)

Snorkelling with Aya

Sea near Kanezaki

Aya’s getting really confident in the sea now. We were snorkelling for an hour and a half, and we swam several hundred metres, but she was fine. The sea was full of box jellyfish (andon-kurage) so it was just as well we were wearing wet suits and rash guards. Lots of stuff to see today. Our favourite was the little squid. It rained while we were swimming; then the sun came out and we saw a rainbow.

Sea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near KanezakiSea near Kanezaki
Sea near Kanezaki

Location: Beach near Kanezaki
Google map: here

Jellyfish & more

Went snorkelling with my friends Bob and Chris in a different place to usual, near a small lighthouse just up the coast from Ashiya. Link to map and aerial photo here.

We immediately realized our mistake of swimming in the jellyfish season! The sea was quite choppy and the waves seemed to have concentrated lots of the little buggers in the cove. I thought I’d be OK with wetsuit, hat and gloves, but still managed to get stung on the face. Also stupidly caught a jellyfish with my gloved hand, which was OK, but then after letting it go I wiped the water from my face and found that the stings were embedded in my glove = not very pleasant at all. By the way, these jellyfish are a kind of box jelly (andon kurage) but they are not so venomous. They can leave a nasty welt across your skin but don’t do anything more serious. However, this will be the last day we get in the sea until next year!!

Two videos:
1) Box jellyfish (2.96MB)
2) Ray (1.48MB)

Phylum: Cnidaria; Class: Cubozoa; Order: Carybdeidae; Species: Charybdea rastonii


Despite the hundreds of jellyfish, the choppy water and the poor visibility, we found quite a few interesting things. When I have time, I’ll try to get around to identifying them:

crabcrab on Boblighthousefishrock fishshrimpsmall blue fishray

Lionfish & Eel

Very exciting dip in the sea today! Spotted a beautiful lionfish (kasago) and several eels (unagi). The lionfish was only about 50m out from a very popular beach, which is a little concerning since it has venomous spines. This is only the second time I’ve ever seen one despite swimming in this bay most weekends throughout the summer for the past few years. I swam around the lionfish for quite a while trying to get decent shots, but it was about 5m deep and I couldn’t hold the camera steady enough. I’ve seen eels many times before, but this was the first time I succeeded in getting photos.
By the way, the other two photos in this blog entry show some kind of flatfish. So well camouflaged until it moves.


Scorpionfish family = Scorpaenidae
Luna Lionfish = Pterois lunulata (but this needs checking)

Eel family = Anguillidae
Japanese eel = Anguilla japonica (but this needs checking)

Friendly fish

Went snorkelling again today – the third time in three days! The tide was out and I managed to hold onto a rock so that I could take some reasonable photos of fish. The best experience was meeting a little yellow and black ishidai who just couldn’t keep himself away from me! I scratched the surface of the rock to release a few morsels and he went crazy, trying as hard as possible to snap up the cloud of bits. I assumed that this was an adult fish but later found out that this species grows up to 80cm long and changes colour completely (see this picture). The young fish are famous for their curiosity.

[As usual I’m not very confident with fish identification, but hopefully these are correct.]

Barred knifejaw (or Striped Beakperch) = Oplegnathus fasciatus = ishidai

Spottedtail Morwong = Goniistius zonatus = takanohadai

A kind of wrasse = Halichoeres bleekeri (?) = honbera (?)

Beautiful sunset today!!


I came across this big octopus (tako) while snorkelling today. It was the biggest octopus I’ve seen – at least 50cm from outstretched arm to arm. It was a bit deep (4m) for me to get a decent picture and it also slipped under a rock as soon as it spotted me. The amazing thing was that it changed not only its colour but also it’s shape/texture. When it was sitting on top of the rock it had white spiny bumps all over it’s body, but then it became smooth and reddish brown when it was under the rock. I wanted to catch it but there was no way it was going to allow itself to be pulled from under that rock!

Snorkelling with Aya

Aya came with me snorkelling at Kanezaki today. It was her very first time and she did really well (especially considering she’s only nine). We swam out about 200m from the shore and snorkelled for about one and a half hours. There was so much to see and Aya couldn’t get enough! She wants to go again tomorrow!

Aya snorkelling (first time) Aya snorkelling (first time)bora (I think!)bora (I think!)
We had some excitement when a huge shoal of 40/50cm-long fish (bora) suddenly engulfed us. They were swimming really fast and a few of them actually bumped into me. I’ve never experienced anything like it before!

The fish above is called ohagurobera in Japanese. Cocktail Wrasse = Pteragogus flagellifer.
[I hope this identification is correct – it looks very different on some fish web sites.]

moon jellymoon jelly
Moon jellyfish = mizukurage

Can you see the flatfish?sponge
Can you see the flatfish in the picture on the left? This was a tiny flatfish and it was incredibly well-camouflaged. I only knew it was there because I’d seen it move. The picture on the right shows a pretty little sponge.

Sea Life

Spent another three hours in the sea today – mainly alone but the kids joined me for the final hour.

Rei and Aya in the seaAya snorkelling

I’m finding it very difficult to get the high quality photos I’d like to take. I guess one of the problems is that I’m only snorkelling and it’s very difficult to keep still underwater because, if I stop swimming, I float to the surface again (wearing a wetsuit). I’m learning to hold onto rocks or seaweed holdfasts with one hand in order to stay still. However, I can only stay down for a minute or so, which isn’t enough time for the fish to come back after I’ve disturbed them. I’ll need to learn to hold my breath for longer!! Also, because I’m only holding the camera with one hand, it’s difficult to keep it steady and manipulate the controls. I don’t know if it’s the camera or me, but getting pictures in focus is tricky. I’m sure my photos will get better with practice.

beautiful little fish (nabeka)beautiful little fish (nabeka)Mullet (bora) - 50cm longMullet (bora) - 50cm longwrasse (bera)a puffer fish (fugu) and another fish hiding under a rockanother kind of wrasse I thinkanother kind of wrasse I thinkSea anemone on rockSea anemone in sandstarfish (itomakihitode)starfish (itomakihitode) and sea urchinsmoon jellyfish (mizukurage) - a bit damagedrock fisha kind of sponge I think (with a hermit crab)there were lots of these tiny fish

Evening on the Beach

I took the kids along to the beach this evening. Nice sunset! We found lots of hermit crabs (yadokari), as usual, and also found the weirdest little crab. It was a species of spider crab (kumogani) that disguises itself by growing seaweed all over its body. It was almost invisible among the weeds! Another interesting find was a ball of shrimps (presumably mating).

sunsetboat in the sunsetAya and Rei looking in the rock poolshermit crab with red feelersdisguised spider crabdisguised spider crabdisguised spider crabball of shrimpsfunamushifunamushi

New Camera

I bought a new digital camera (Sony Cybershot DSC-P100) and its underwater housing (MPK-PHB). Only cost 48,000 yen in total. The pictures below are from my first day using it (= today). I was in the sea for three hours and could hardly walk when I got back to the beach!! [Apologies for the lack of identification.]

View from the seaNice portrait!big fish swimming byunderwater worldsea slugsea spongeFish under a rockSwimming away from me fastvery pretty fishrock fishfish among barnaclesfish among barnaclesshoal of fishshoal of fishSea hareyellow fish