When I visited Lembeh in September/October there were flamboyant cuttlefish around in numbers that I have never seen before. On more or less every dive, we saw one or more flamboyants. Blue ring octopus were not as common, but still there was hardly a day when we didn´t see them. This is very much in contrast to the situation now, at least considering adult octopus and cuttlefish. We have seen some, but while still here, they are not nearly close to the densities experienced in September/October. Where did they all go?
Actually, cephalopods, the group that octopus and cuttlefish belong to are quite short-lived. Not only that, they only reproduce once and then die! This pattern of reproduction, where an individual grows for almost all its life, mates and then die, are called semelparity.
Other animals continue living after reproduction and produce other litters some time after. Such a strategy, with multiple reproductive events after the onset of maturity, is called iteroparity.
The answer is that all life histories, that is the allocation of energy over time, consist of trade offs. Food is seldom unlimited, and if it where, time or developmental rate would limit the options available for an animal. The first ting that needs to be realized is that reproduction, having offspring, is expensive. Experiments have time after time verified that reproducing individuals of a lot of different species die earlier than non-reproducing individuals. That is the first trade off, choosing between a long life or offspring. And having no offspring is a fundamental screw up in nature, as your genes get lost for the future, so choosing long life rather than reproduction is not an option for animals looking for success in life.
The second trade off is that costs are related to the effort that is put into reproduction. Everything else equal, the more offspring that is produced, the less survival or future growth rate an individual will experience.
The third important trade off is that an individual need to keep significant amounts of energy reserves in order to survive over long time in the future. Up to around 90% of the energy budget might have to be allocated to future survival if that is the goal. Thus, an individual can produce a vastly higher amount of offspring in one reproductive event if no energy is saved for future survival. Thus, if an individual irrespective of reproduction faces quite high mortality rates, it could obviously be advantageous to “go all in”, reproduce with all the effort you can, and save nothing for a very uncertain future. And that is exactly what cephalopods do, invest all they got in one single “big bang” litter instead of saving themselves for another day.
The cool effect of that here in Lembeh is that there now are quite a number of minute, fully colored flamboyants around. The young flamboyants are really cool, brightly colored and have a lot of attitude.
Whenever you visit the same dive area several times, some dive sites seem to consistently deliver more than others, and, correspondingly, some less than you would wish. Here in Lembeh my favorites are the Aer Bajo sites and Hairball, where many uneventful starts of dives have been turned around to glorious experiences. The different TK sites on the other hand have for some reason not really caught my interest that much, despite that if I really think hard I actually have seen some really neat animals there. My expectations for yesterday´s morning dives were less than stellar, as the first dive was in Nudi retreat (coral dive, why??) and TK 3. Nudi retreat delivered a couple of cool Xeno crabs as well as a beautiful soft coral crab, which was fine, and perfectly OK. Happy with that. TK on the other hand, in the words of a well known dive resort owner, just kicked the balls out of any kind of negative feeling about that site.
Paulus, my dive guide for the day, first found a weird flat crab buried into the rope sponges that are so common in TK (pictures coming in a later blog). Just after that a great Janolus nudibranch posed nicely,
followed by a number of “commoner” nudis, and a beautifully colored devilfish, showing of its pectoral fins.
A couple of minutes later in a small patch of rope sponges and debris, two beautiful frogfish and one common sea horse were found.
That was just the start. After that, less than 5 meters apart, a flamboyant cuttlefish was hunting,
a hairy frogfish came walking by, and, finally,
a coconut octopus did his (or her) amazing show with a couple of beautiful shells, hiding, digging, watching me and walking around with the shells.
So, TK, I am officially sorry for my negative attitude. TK after this climbs significant steps on my favorite dive site list. Simultaneously, my wow for this trip of concentrating the photo shooting to a few of the best subjects on each dive, was blown to pieces. But what can you do, this was like letting kids loose in a candy store, Danes loose in a beer pub, Djengis Khan loose in a village of pacifists or Simon loose in a camera store!
I finally got around to posting my Hairy Octopus video, we’ve seen 3 in 3 days now here in Lembeh!
We’ve been having fantastic diving recently, and we have been having some fun with the guys taking pictures and also annoying out yearly repeat guest, Mood.
Mood has been to Lembeh every year for the last 5 years and still does not have the hairy octopus, he always missed it. We see it when he has a bad ear, when he skips a dive, or they find it on the same dive he is on but he has gone off looking for something else and is too far to call over.
The other day the boys took me to try to find the Hairy Octopus for the first time, and they found one on each of the first 2 dives – they haven’t found one for a while so there was quite a lot of excitement, and obviously a lot of bravado beforehand, and even more afterwards.
I was pretty amazed by this creature, so i thought it only fair that I let them click off a few shots whilst we were waiting for the guides to find Mood.
Here are their shots!
The Hairy Squat Lobster (Lauriea siagiani) lives in the crevices of the large barrel sponges here in the Lembeh Strait. They typically hide pretty well making it tricky to photograph them, and extremely hard to video them. I found this guy on a night-dive and he was sat out and moving around, in fact he seemed to enjoy the video lights bringing him plankton. In these few short clips below you can see the function of the hairs on this critter – they trap stuff for the ‘lobster’ to eat. You can see him comb through his ‘do and eat up the bits he collects a couple of times. In my experience of Indonesia over the last 6 years, their diet generally consists of fish poop that ends up settling on the sponges.
Squat lobsters can be found in almost every square meter of the Lembeh Strait, but the Hairy Squat Lobster is the most beautiful and sought-after.
Update 1. In the blog on cephalopods I mentioned that we still had a couple of species to be seen. Not so now, we saw an algae octopus yesterday and on this morning’s first dive, not one but two hairy octopus were found. I guess that´s it for the cephalopods! Maybe not if we get really picky about the number of bluering species in the area, but as even experts seem to have quite some trouble defining that, we will just leave it at bluering for now.
Update 2. In the blog on seahorses and relatives, there was a blaring omission. No pictures of the pygmy seahorse itself, the Hippocampus bargibanti. No such omission now, here is a bargibanti from today. Interestingly enough, I have a distinct feeling that there are way more bargibanti in the area now than a couple of years go when I first came here.
Update 3. The seahorse blog did not have a picture of a pregnant ghost pipefish. Here is a pregnant female with the extended pelvic fins holding the eggs.
Update 4. There was some discussion here at NAD on whether frogfish lack gills, lack gill covers or neither. Frogfish have gills, have no proper gill covers but exhale the water exchanging gasses over their gills through a little hole at the base of their front “feet” (“arms”, “legs”?). The holes can be used as water jets, propelling the frogfish along quite like a cephalopod.
Talking about frogfish, there will soon be a new batch of small hairy frogfish around. A couple of hairy frogfish, where the female is very full of eggs, seems to be having a cozy day in the strait today, spending some quality time together. The couple will probably heat up the action tonight, so look out for a floating egg masses in the strait tomorrow. Judging by the size of the female, it will be a big one!
Frogfishes! Always fun to see and wherever they are found often the stars of the local diving critters. Lembeh delivers frogfish in so many shapes, sizes, and colours, that you could spend a week or more just checking out the varieties here in the strait. Well, maybe not shapes as most are more or less shaped like a hybrid of a ball and a fish, with the expected agility of such a creature! The last two days, we have seen painted, spotfin, giant, warty, hispid and striated frogfish and the striated has shown both it´s shorthaired and longhaired version.
So what are frogfish? All frogfish are small to medium sized sit and wait predators, that tend to find a more or less species-specific spot where their specific camouflage can be used. As an example giant and painted frogfish are most often found in or next to sponges, where the frogfish blends in in an amazing way with the colour and texture of the sponge. Another example is the hairy frogfish, which most often will be found right next to small colonies of corals with long tentacles on their polyps, giving a surprisingly efficient illusion of the frogfish being part of the coral colony.
Making the illusion even more thorough, frogfish do not have gill covers like most other fish, but expels the water flushing over their gills through small holes at the base of the pectoral fins. Thus no moving gill covers will alert any predator or prey that there is a rather tasty or dangerous, depending on perspective, frogfish just in front of you.
Frogfish, or anglerfish, which is their proper name, use their famous fishing rod called an illicium that is tipped with a lure, a so-called esca. The lure is waved in front of the mouth of the frogfish and, as the frogfish itself blends in with whatever it is sitting on or next to, passing fish cannot believe their luck when they see such a tasty morsel being available. The passing fish will approach and try to catch the lure, but will soon find itself in the stomach of the frogfish. In contrast to the sluggish and otherwise slow life style of frogfish, they actually are able to perform one of the quickest movements in the animal kingdom. The extension of the mouth and subsequent inhalation of water is over in milliseconds, often giving an illusion of pure magic when one observes a small fish in front of a frogfish suddenly just not there any more!
This afternoon’s dive will partly be spent in search of the elusive Randall´s frogfish. This small species is very cryptic, spending most of it´s time in rubble or clumps of dead sea weed. It is really hard to find, so luckily we can have a try tomorrow again. And the day after! The good thing about looking for almost impossible stuff here in the strait is that you will see so much cool other stuff while trying, so it is highly likely that we more or less will forget whatever it was we started out with looking for!