Zilch - Nautilus Pompilius

[DWhatley]

Zilch seems to want attention at different times of the day and night. He will come to the front and bob or swim back and forth. If I put my hand in with food he usually maneuvers toward it, usually taking the food but sometimes only nibbling. He will stay close to my hand and allow me to "pet" his hood for perhaps 2 minutes and then slowly swims away. He seems to have stopped trying to taste my fingers (or they smell less like food) but will sometimes place one or two cirri on my hand while being "petted". I hope he is not lonely.

 

[DWhatley]

Zilch has been going lower in the tank during some parts of the day when the chiller is off. He is still not neutrally buoyant and I am not sure if the slightly warmer temperature near the surface is the reason or if he is slowly recovering. I try not to approach him when he is deep as he will often release his hold on the tank side and zoom to the top. I know he can propel himself downward without having to "walk" down the wall so I am not sure why he does not slow his ascent. It may be that he does not understand his buoyancy problem.

 

[DWhatley]

Zilch cannot yet hunt (making progress with buoyancy - see next post) so I hand feed nightly and he seems to have the procedure well understood. We use the front right corner or the tank to the top middle as the feeding area. He will sometimes go to the right corner and start rocking when he sees movement in the kitchen. We understand this to mean he wants either attention or food He seems to have a positive reaction to very light petting along any of the three grooves in his hood. I know there is sensation there as initially if I accidentally touched the hood during feeding, he would react by withdrawing into his shell. Now it appears he may like the feeling of a slight rub. I am still trying to document this as a positive action/reaction (for myself as well as others). I can say positively that he no longer withdraws and stays in place when I extend a finger to pet the hood. He will leave when he no longer wants petting but does so slowly and does not withdraw into his shell. Tonight, with his buoyancy under better control, he held himself below my fingers and rocked when I did not move my fingers. This could be a fluke and could be that he wanted more food . I don't want to touch too much as I don't know if there is a slime coat that could be negatively impacted but will still experiment to see if I can justify my understanding.

 

[DWhatley]

Zilch is starting to be able to control his buoyancy. He is not yet neutrally buoyant but can now swim (without using the wall) down about 2.5 feet (the tank is 3 feet deep), hold himself there for a long period of time (it appears he stayed there most of the night) and control his ascent. I am particularly happy to see him controlling his ascent as, up until yesterday, he floated rapidly to the surface from any depth and hit the top of the tank (fortunately not with great force). I don't know if this is the result of fluid regeneration or if his slight, but noticeable, growth is giving him control. He only descends to his maximum depth along this short wall but has started swimming across the front of the tank, still ignoring the rocks.

He normally sleeps in the back V of the pentagon.

 

[DWhatley]

I ordered frozen food last week and decided to try silver sides as a treat and alternate food for both Zilch and Shiitake. Zilch became quite excited when I put the fish in the tank (extending his cirri (the pink appendages that extend from his tentacles) and rocking, I wait to offer food until he is in his feeding corner). He took the fish and held, held it sideways and only had it a short time but when I retrieved the remainder it looked like this:


I believe he went for the innards first . I have learned to reoffer dropped food. I don't think they have manipulation abilities and dropping food is not an indicator of being finished. When he does not want food, he will blow at it with his siphon, much like an octopus. The second time the fish was offered and accepted, the tail was bitten off and discarded. The third and final time I did not see anything of the fish on the substrate or floating.

 

[cuttlegirl]

I believe he went for the innards first .

Yummy...

 

[DWhatley]

Zilch is FINALLY starting to investigate the rockwork. I think he likes fish as he spit out his second piece of shrimp tonight and was hesitant with the first piece but was not offered the food until came to the front for feeding. Since he discovered the rocks, I used a feeding stick (a VERY long "feeding" stick ) to put a piece of fish near him. Unfortunately he grabbed the pinching part of the stick as well as the fish so retrieving the stick brought him back to the surface and he went to his feeding corner to eat but this is the first time he has taken food from anything but my hand. I love feeding him but want him to hunt on his own. It would be a lot to ask someone house sitting to hand feed all the critters



I can't help but think Zilch wants human attention. After he rejected his second piece of shrimp he came over to my hand and pushed against it while holding on to the surface skimmer. If I touched the side of his hood he moved away but came back. If I touched the center groove he remained in place and rocked, keeping in contact with my hand. However, he also held my finger with his cirri so maybe he just wants to taste my fingers

 

[robyn]

I'm glad to hear Zilch is still looking good! Ngdo asked a question above about lifespan - I think with good water quality and correct diet they can go for many years in captivity - most of the short durations we hear about are from non-optimal housing - overcrowding, overheating and overfeeding. As for being bitten - I have no doubt at all that they could cut skin - the buccal mass is massive compared with squid and octopus, and the beak is just as sharp... I do not believe they are venomous, but certainly they are covered in nasty bacteria. At least they are slower about biting you that squids are! But take care with your fingers all the same....

 

[DWhatley]

Thanks @robyn. As with octopuses, I am cautious with my fingers and I do think Zilch may want to nibble. Sometimes he attaches to my fingers with multiple cirri and pulls his body closer. When I try to free my hand he will come slightly out of the water before releasing. When he does this I am never sure if he is simply anchoring to my fingers, if my fingers taste like food or if he is just curious about how my fingers would taste.

I suspect these guys may have individual personalities and am not surprised you found them to be more intelligent than they look (my son thinks they look "dumb") but it is hard to tell much about intent with an animal that does not change color, body posture or eye expression. One consistent observation I am trying to translate is his rise to the surface when I approach the tank (usually trying to get a picture of how low he is ). I am assuming he cannot see well enough to identify me as an individual and he does this before I put my hand (or even if I don't) in the tank. He may be expecting food but will do this even if he is not hungry. I need to experiment and see if he rises when Neal approaches as well (I am the primary feeding slave).

I think they (or at least Zilch) may be far sighted and can visually detect movement better at a distance, akin to a fixed focus lens setup for landscape rather than portrait (Brownie cameras come to mind ). The kitchen is about 15' away (as the crow flies) and he seems to see movement there very well. If he is awake, he will start pacing at the front of the tank when someone is moving around in the kitchen. If he is sleeping he does not seem to notice anything and it takes a good bit of splashing and water movement to "wake" him up. When I am in front of the tank and place my fingers inside at the top, he seems to have a bit of difficulty determining their location. Usually, he goes to his front corner and extends his cirri but does not come directly to the center to my fingers. If I am patient he will eventually find my hand but it takes several cross tank (back to front) attempts along with some odd navigation (like a tacking sailboat).

I suspect Zilch will become neutrally buoyant as he grows (I want to try to figure out sex but don't want to take him from the water). It would make sense that they create more fluid as they grow and his depth accomplishments have come after detectable shell growth. Do we have a clue on what the fluid is composed of and what foods might encourage production?

 

[DWhatley]

Three FEET! . Tonight Zilch managed to go to the bottom of the tank - YEA! He is holding on to the wall but not struggling to stay down. Zilch also took a short interest in the rocks. I don't know if he dropped part of his fish and picked it up by himself or not. I usually have to offer the initial uneaten part a second or third time. I found the last fish offering inside my small top skimmers this weekend so I checked there first when looking for the uneaten section but found them empty.

 

[DWhatley]

This is the first time I have seen any interaction with the cleaning crew. One of the shrimp will swim to the top of the tank when Zilch is up there but I have not seen it come very close. Zilch did not seem to mind the shell cleaning as long as the hermit did not touch his soft parts. However, when I fed Zilch, he chose to go to the other corner of the tank to eat.

 

[Nathalanti]

You seem to be having an exciting and enjoyable time with this little guy.

I'd suggest to check gender, life up it's tail and look... it works with kittens... good luck finding the tail.

On a more serious note have you any idea of it's current age? how long did the uni student look after them before they needed re-homing? Also does any large scale aquarium have any that they can verify ages on?
Kelly Tarltons in New Zealand doesn't seem to have any Nauts but have active Octo's.

 

[DWhatley]

Sexing a naut is not too different from that but I have never done it and am a bit intimidated to try (@gjbarord had an article describing the method and what to look for). Like octopuses, you can't order one by sex so even if I thought about getting Zilch a companion, it would be pure luck to have a pair. I would love to try to raise them but don't even know how well I am doing with Zilch at this point. If he/she survives a year I may consider acquiring another (possibly 2 more for better odds of a pair).

I have (as would be the case with any wild caught) no clue on Zilch actual age but he/she is still an adolescent. When they become adults, the shell will no longer have the tan stripes. The half inch or so of new growth does not appear to have any striping but I will need to see about 3 times this growth to know if he/she is entering adulthood (assuming the shell is healthy - an issue with aquarium kept animals). Several aquariums (I saw several eggs at Steinhart - California aquarium, research institute) have them and see successful mating and eggs laying but very little is known about hatchling survival. Eggs take about a year to mature and no one knows where they are laid in the wild. It appears that new hatchlings need warmer water but last I saw, only an aquarium in Japan has successfully raised an egg (5 years and counting).

 

[Rhodi Hawk]

This is the first time I have seen any interaction with the cleaning crew. One of the shrimp will swim to the top of the tank when Zilch is up there but I have not seen it come very close. Zilch did not seem to mind the shell cleaning as long as the hermit did not touch his soft parts. However, when I fed Zilch, he chose to go to the other corner of the tank to eat.

That video of the little hermie preening Zilch just tickled me. For some reason it made me think of an old Bugs Bunny cartoon, the one in the mad scientist's (boo!) mansion with the big red monster in sneakers. The hermie was like Bugs styling the monster's hair, going on about how monsters are the most INNNteresting people.

 

[DWhatley]

I gave Zilch his second "bath" this weekend. The first time I removed his green algae, I used a soft bottle brush and he was not at all happy with the process (squirted water at me). This time a used a Mr. Clean scrubbing pad and the process was much better accepted.

He picked up a dead fiddler crab from the rock after I dropped it from the feeding stick this weekend. This is the first time I have seen him feed himself. Later, I put two live softer shelled saltwater crabs in the tank that I knew might not survive. Within minutes he had one in his mouth (I initially thought he was still eating the fiddler). I don't know if the crab died and he found it or if it was just slow acclimating to the colder water but I am very glad to see that he is hunting for and finding food. I have more of these crabs and will watch to see if he is catching slow live animals when he is hungry. He pays no attention to the live shrimp that swim near him.