Help needed with my Sepia Bandensis Dwarf Cuttlefish eggs

[ReefGirlVicki]

Cuttlefish have been something I’ve always been fascinated with & have wanted for as long as I can remember. Over the years, I’ve tried to do as much research on them as possible. I’m mainly interested in Flamboyant (Metasepia pfefferi) & Dwarf (Sepia bandensis) but unfortunately there is still very little information out there! They are also very difficult to find here in the US

After searching the internet weekly trying to find some & being on a waiting list for almost 2 years, I finally woke up last Monday morning to find that I had an email notifying me that the Dwarf Cuttlefish eggs I had been patiently waiting for were FINALLY available!

Without even checking my bank account or worrying if I had any upcoming bills due, I immediately ordered whatever they had left fearing that if I didn’t act now, they would quickly sell out & I’d possibly be left waiting another 2 years to get some. Unfortunately they only had 5 eggs left so I’m a bit worried about my successful hatch rate. I’d love to end up with atleast 2 but I’ll still be happy even if I end up with only one!

I actually ended up taking off from work the day that I ordered them to start preparing for my new arrivals. I specifically asked for them to be delivered on that Friday (which I also took off from work) so that I would have the week to get everything in order - even though I had done as much research as I could & had my 20 Gallon Long Softies/Macroalgae Tank all set up & waiting for the day that I finally got some eggs, actually getting them was very last minute!

I knew I needed to get a Breeder Net to keep the eggs in (I had an Amazon Prime Wishlist already set up with a few different ones that I researched/read good reviews on) I ended up ordering the Penn Plax Deluxe Net Breeder which is actually really nice other than the fact that the suction cup on it isn’t too great - it does stick but slowly slides down over the course of the day so I have to move it back up every morning.

I had already previously researched & found a place where I would be able to purchase Mysids to feed once the eggs hatched - they are very hard to find in US & usually extremely expensive if/when you do find some available especially with shipping! I ordered both Mysids & Grass Shrimp from Sachs Aquaculture which is supposed to be here early next week. Right now I’m also researching culturing Mysids myself which apparently isn’t an easy task but one plus is that since I already hatch baby brine daily for my Dwarf Seahorses, I’ll have plenty of it to feed the Mysids to hopefully keep the little cannibals from eating each other lol And I usually already have some Grass Shrimp on hand since that’s what I feed my Frogfish. I keep them in a little “Critter Keeper” with an airstone. Does anybody know or have suggestions on what types of crabs I can try feeding them? Are Fiddler Crabs okay?

I also decided to order some more fresh Macroalgae to put inside the Breeder Box with the eggs - I got Clean Cheato & Clean Pom Pom Gracilera from AlgaeBarn.


As I mentioned previously, I haven’t had much luck finding information on Sepia Bandensis. Right now I am looking specifically for information on the hatching process & was hoping I could find some help/answers here in TONMO

I bought them from BlueZoo & there is absolutely no information on how to hatch them, I’m not sure how far along the eggs were when I got them & they are on the “restricted list” which means there are no guarantees on if they hatch for me or not. The only thing it does say is to feed them Baby Brine Shrimp after they hatch - from everything I’ve read over the years, I’ve come to understand that you should NOT feed them baby brine as most will not survive if that is the only thing they are fed which is why I ordered the Mysids. But since I already hatch baby brine daily, I will probably offer them some along with the Mysids.

I’ve had the eggs since July 31st so it’s been about 9 days so far. They all arrived jet black with little tiny stems attached to the tips. One of the 5 eggs was bigger than the rest (about the diameter of a US quarter) & the black was starting to come off slightly. That egg has now started to shrink, another egg has gotten slight larger (now the size of a US quarter also) & then other 3 eggs are still the same small size (about the diameter of a US dime) & still jet black like the day they arrived.

Some Questions...

Is it a good or bad thing that the one bigger egg has started to shrink?

Good or bad that one has gotten slightly larger?

What about the fact that the other 3 eggs are still small, jet black & haven’t had any changes at all?

Should I have my power head pointing a little bit more towards the Breeder Box slightly tumbling the eggs? (currently the tank has fairly high flow & there is circulation going through the Breeder Box but with the way I have the power head aimed, the eggs are just sitting at the bottom of it not moving much.

What temperature should I be keeping the tank at while waiting for them to hatch & also what is the ideal tank temperature once they do hatch? I currently have it at about 79F - 80F but I’ve read conflicting things on temperature while hatching - some say cooler water is better (low to mid 70’s) while I’ve also seen people say higher temps are better for hatching (upper 70’s to low 80’s) Most of what I read on tank temperature for juveniles/adults tends to say mid 70’s but I’d love some other opinions on it.

I know that people say to look at your eggs with a flashlight to see if they are viable/fertile but does anybody have some other tips/tricks or ideas? The 2 larger ones, I can kind of see what looks like a little speck of light inside but I don’t seem to see any type of movement in there. Not sure if I need a brighter light, a stronger magnifying glass or what. The 3 small eggs, I see nothing - just jet black.

How long do they take to hatch? I’ve read everything from a week to a month! I’m not sure how far along they were when I got them. My only clues to try to figure it out is that I got them a week after they were listed for sale & now I’ve had them a little over a week so my guess would be about 2 weeks old

Is my 20 Gallon Long going to be big enough for 2 adults? I have my 37 Gallon High that I could also use but that wouhave to be set up from scratch & cycled first.

What do you think is the best type of substrate for them? From everything I’ve read, it appears fine sand is the way to go but is that a must? I’m not really a fan of it - it blows around way too easily especially with higher flow & always clouds up the tank if you have to clean/move anything in there. I read a very interesting study on Cuttlefish substrate preference (which I’m sure a lot of members here have also read) but it was a bit confusing to me so it didn’t really help me with an answer. Right now the tank that the eggs are in has about a 2 inch mixture of medium granule sand & crushed coral/aragonite. It’s also got lots of big pieces of Live Rock.

I’m sure I will have plenty more questions if/when they do hatch but these are just the immediate questions that I’m in need of answers for. Hoping someone here will be able to help me out & fingers crossed at least one of these guys successfully hatch for me after my two year long wait to finally get my hands on some eggs!

 

[pkilian]

Hello! I have worked with bandensis of all age ranges before and have a few answers to your questions.
1- about eggs changing size, the growing is a good sign, the shrinking isn't necessarily a bad sign. Typically, healthy and fertilized the eggs will continue to grow in size and lose their opacity and become lighter in color but sometimes they can get a bit smaller when the animal is growing inside. An easy way to check the eggs with a flashlight is to gently move them into a clear cup (keeping the eggs submerged in the water the entire time) and then lift that cup out of the tank and shine the light in from the bottom of the cup. You should be able to see some small amounts of development going on inside the egg. Either a yolk present or a very tiny baby bandensis inside the egg. You shouldn't need that bright of a light to see the development. I wouldn't worry too much about the eggs that haven't changed size yet. If they continue another week or two without changing shape or size at all then they may be unfertilized or duds, but until then I wouldn't worry too much about them. You are correct in reading that the incubation time can be upwards of a month.

2- A tank temp of 78-80 deg is good for incubating eggs and for growing up juveniles as well. Once your animals grow to be about 1-1.5" long, you might want to slowly decrease the temperature in order to increase their longevity. By slowly I mean reduce it by no more than half a degree a day until you have dropped it down to around 77 deg, maybe a touch colder if you really want to slow your animals growth down.

3- a 20 gallon tank should be appropriate for the time being, but once the animals are close to sexual maturity (in about 2-3 mo. post hatch) you might want to put them in individual tanks to prevent territorial fighting or aggressive mating (which can be a problem if you have two males, or a male and a female). Typically this isn't a problem in large enough tanks, and some of this territorial-ness can be mitigated by having a good aquascaping design. You will know if you will need a second tank after watching the animals interact with each other, but it may be best to get started on that second tank once you see how many hatch out of the eggs.

4- On the note of aquascaping, cuttlefish of all age range need lots of ways to hide and block line of sight from each other. Hatchlings and juveniles like fake plants and fake corals that they can hide underneath and inside. This is what I have used in the past to great success. These corals provide both ample hiding spaces when they are young, and are an extremely good substrate for females to lay eggs on once they reach sexual maturity. I would highly recommend having aquascaping elements like the coral or some fake plants in your tank. For substrate, you probably don't need anything if you are worried about it. Bandensis spend a lot of their lives suspended in the water column, and if you give them lots of "shelves" to rest on (like the coral I linked has) they won't need to settle on the bottom of the tank.

5- On the topic of food: I would recommend against feeding them just brine shrimp. They are not very nutritious and are much too small for even the newly hatched bandensis. Mysids are the way to go. One tip is to make sure to feed your mysids brine and your grass shrimp krill powder or whatever food you have on hand before feeding them to the bandensis. This serves two purposes, one is that itenriches your mysids and grass shrimp so that they are more nutritious. Second, the red color of the brine and krill powder shows up as a bright red dot in the gut of the mysids and shrimp, making it easier for your bandensis to find the prey.

You can feed mysids from the first day they hatch until your bandensis are large enough to take very small grass shrimp. It may be worth your time to start reserving any small (.5" or smaller) grass shrimp you find in a separate tank to feed to your bandensis when they are large enough to transition from mysids to grass shrimp. Transitioning food for bandensis is probably the most difficult part of raising them after they hatch out. You will want to always be feeding them prey that is about the length of the distance between their eyes. Hatchlings can usually take on larger mysids but I would still be careful to not add too many mysids or too large of mysids at first. I can give more advice on feeding and transitioning feeds in the future if you have more questions.

I hope that helps! Let me know if you have any followup questions and I'm happy to answer them.

 

[ReefGirlVicki]

Thank you so much!
That was extremely helpful!

I guess my only other question right now would be, should the eggs be slightly tumbling or should I be manually gently moving them around on occasion? Or is it okay that they just sit still at the bottom of the Breeder box?

There is plenty of surface flow in the tank & medium flow throughout the tank but on the side of the tank where the box is, I’ve been keeping flow minimal as I wasn’t too sure if it would disturb the eggs.

 

[pkilian]

a gentle flow around the eggs is appropriate. It should not be blowing the eggs around, they should mostly just be moving gently in the flow. Can you post a photo of your current tank set up and the location of the eggs in the tank? They need less agitation than other species of eggs do. Mostly just enough flow to keep copepods or other little critters from crawling on the eggs.

 

[zzyz]

Hello! I have successfully raised dwarf cuttlefishes from fertilized eggs to the stage where they are capable of preying on adult shore shrimps. I hope you find some of my answers helpful:
1. As long as the eggs were fertilized, they achieved a hatch rate of 100%. I didn't notice a significant change in size during the incubation process. Perhaps the best way to inspect the development is by looking inside the egg. It is easy to do so with respect to white eggs laid by common cuttlefishes but a bit tricky for black eggs as you have to watch very carefully under strong light.
2. As long as the tank is well oxygenated, little flow is needed for the eggs. I had macro algae cultured in my UAS. So I just left the eggs in the breeder box with almost no flow. And they grew pretty well.
3. I heard that cuttlefish's longevity was sensitive to water temperatures. But they could survive in a wide range of parameters. For me, I set temperature at 75 where most marine creatures felt comfy.
4. There is a paper published on Zoological Studies that it took about 672 hours on average for the eggs to hatch. My experience with common cuttlefishes and dwarf cuttlefishes are consistent with paper findings. It took about a month to hatch.
5. 20 gallon would be sufficient for a dozen hatchlings. Cuttlefish juveniles are quite social and never fight. I had 8 hatchlings in less than 1 gallon for two months and they were pretty happy with each other.
6. I had two cuttlefishes escaping the breeder box and found they liked rock/sand environment much more than the breeder box. As you have a species only tank, I guess they will pretty enjoy their living.
7. Perhaps the most challenging part is live food. They don't eat brine shrimp or their nauplius. I feed a mixture of shore shrimp larvae, crab larvae, pods and amphipods in the first week post hatching.

I have a video on my journey with cuttlefish hatchlings. Take a look if you are interested.

 

[micstarz]

Following on topic of egg incubation - I came across a cluster of cuttlefish eggs (unknown species) at my local beach while snorkeling. Plucked one and took it home, left it in a vodka bottle with beach water and it hatched. So it seems they are hardier than most think. Now in the process of rearing the hatchling. Feeding it locally collected amphipods.