Cuttlefish sex vs. temperature of the eggs

[squishy1]

Uploaded with ImageShack.us

 

[DWhatley]

As I recall from CuttleGirl's group, the early and late eggs did not do well but the ones in the middle of the brooding cycle survived.

 

[squishy1]

From all the reading I did before I got the cuttles, I read that numerous times as well. The viability of the eggs goes up with age and then hits a peak, and then precedes to decline again when they get older. I figure I would try to sell the first egg clutch for really cheap since out of 20 eggs, id guess maybe 4 or 5 would hatch. Especially since mine are still young, just about to hit 3 1/2 months.

 

[DWhatley]

You might want to watch the first eggs and not offer them for sale unless you see development.

 

[squishy1]

I really just wanted to gauge local interest in the eggs, and I'm glad I did because I didn't get any interest in them at all. I'm trying to plan ahead because they're laying egg after egg after egg. i think i'm past 50 eggs total now, 3 egg clutches. Since no one around here wanted any eggs I spoke to the Birch aquarium and I'm going to give all the eggs i have now to them.

 

[squishy1]

more clutches

 

[DWhatley]

Baby A all over again (Cuttlegirl kept a very prolific female some years ago)

 

[squishy1]

Ya I remember reading some of that journal. I'm not sure exactly how many females I currently have, its either 2 or 3. I definitely know I have more males than females with all fighting they do over the females. I'm constantly seperating them to prevent them from killing each other. I've walked into the fish room several times and caught a male with another male in his tentacles throwing him around.

I'm hoping to find another egg sack hidden under the rocks in the next few days. I gave all the ones I had to the birch aquarium the other day. I got the see how things looks behind the scenes. Also got to see what nautilus eggs look like up close. I think the curator was trying hard to convince me to try breeding nautiluses. But after reading and hearing how loud they can be (banging their shells into the side of the tank) along with the daily temperature change requirements (daily migrations from deeper water to shallow) I think that's a full time job in itself. I also couldn't imagine having to take care of an egg for a YEAR in hopes it might hatch.

 

[DWhatley]

What a great experience! I hope you keep current with the curator as exciting things might come from the relationship! So often the aquarium people want nothing to do with hobbyists and I think both miss out on ideas that are not shared.

 

[squishy1]

Yes I got a lot of knowledge from them, and I think I may have passed some knowledge onto them. I mentioned one of the issues I've been having with the bandensis is losing interest in particular food items, specifically the bay ghost shrimp from the beaches here. At first they ate them like candy, but now they show little interest in eating them. He mentioned it may be a nutritional deficiency in that food source.

There was also this:
Rain Brings Urban Runoff to Beaches

It makes me re-think catching food at the beach to feed the cuttles. If it isn't safe for humans to go in the water, not sure how it would be safe for anything in the water.

Rain Brings Urban Runoff to Beaches

October 12, 2012 | 11:12am



After the first appreciable rainfall of the season, there's a general advisory for the County's coastal waters.

The Department of Environmental Health warns swimmers, surfers, and other ocean users that the levels of bacteria can rise significantly in ocean and bay waters, especially near storm drains, creeks, rivers, and lagoon outlets that discharge urban runoff.

Urban runoff may contain large amounts of bacteria from a variety of sources such as animal waste, soil, and decomposing vegetation. While many coastal storm drains in the county are permanently posted with white metal warning signs, additional temporary warning signs are not posted for general advisories. Activities such as swimming, surfing and diving should be avoided in all coastal waters for 72 hours following rain. This includes all coastal beaches and all of Mission Bay and San Diego Bay. Elevated bacteria levels can persist after a rainstorm depending upon the intensity of the storm, volume of runoff and ocean and current conditions.

Environmental Health has also issued a water contact closure for the ocean shoreline at the Tijuana Slough National Wildlife Refuge and Border Field Park due to sewage-contaminated flows from the Tijuana River entering the United States. Signs will remain in place until sample results indicate the ocean water is safe for recreational use.

 

[DWhatley]

Good to see some monitoring, scary as all get out that it is that bad. Roy has reported octopus losses from crabs collected in certain areas so your findings support the concern of collection area. What would be interesting to test is the shrimp if the aquarium has the facilities. If the cuttles KNOW the food is bad, that could add some very important information. I am thinking particularly about the loss of the mass migration to north AU.

 

[mucktopus]

I am not sure about the temperature of the eggs specifically, but I have seen abstracts of studies which refer to sex ratios of clutches being affected by temperature (for S. Officinalis). Here is one reference (this seems to be a powerpoint of the same paper; slide 11 discusses temperature effects: colder means more females, warmer means more males). I am not sure how reliable this data is, but this is one source that partially backs up the claim that water temperature determines the sex ratio.

I was unable to find anything about the fact that it was the egg temperature as opposed to the general temperature of the water during the breeding period.

Very interesting! In Mangold's review of reproduction in Ceph Life Cycles she mentioned the gonad being differentiated (or at least that's as early as you could tell) around the time of hatching, and that differentiation doesn't appear to be under hormonal control. But there's plenty of room to better understand this process!

 

[cuttlegirl]

Glad to see some bunches of eggs. Good luck finding homes for all of them... I think Baby A laid something like 224 eggs...