Jellyfish ID?

[betareef]

I was catching some local fish and the water I transported them home in, happened to have some baby jellyfish in it. Two types, one is the typical flapping umbrella type, and the other a ball with rows of flagella propelling it gently along. Both only about 1cm across, so I struggled a bit, but finally got some pictures

 

[WalkerLovesTheOcean]

These were caught in Australia?

If so,

The umbrella jellyfish is likely a small hydromedusa. It will be hard to identify it further.

The ball with rows of flagella is a comb jellyfish, likely from the species Pleurobrachia.

 

[betareef]

Yes, Australia. Thanks for the help. Wonder how long they'll live in the tank - I like them

 

[ISpeakForTheSeas]

The umbrella jellyfish is likely a small hydromedusa. It will be hard to identify it further.

The ball with rows of flagella is a comb jellyfish, likely from the species Pleurobrachia.

The first one is likely a Clytia species hydromedusae - the species are indistinguishable without DNA evaluation during the medusa stage.

For image comparisons:

Hydrozoa - The World Hydrozoa Database - Clytia Lamouroux, 1812

www.marinespecies.org

Diario de f-sundw · iNaturalist Mexico

mexico.inaturalist.org

Development of the hydrozoan <i>Clytia gregaria</i>

This is Clytia gregaria , formerly known as Phialidium gregarium . The instructor of our Embryology class collected many adult individuals...

invert-embryo.blogspot.com

I'm fairly certain your specimens are Pukia falcata, as it seems to have the crescent-shaped tentacle bulbs (the two "y-shaped" white parts sticking off the central white white part); this would also make sense given that you're in Australia, where Pukia falcata is reportedly more common than Pleurobrachia (though this wasn't known until relatively recently).

https://www.researchgate.net/publication/242650791_Ctenophora_of_Australia

 

[betareef]

This fascinating. Maybe I should start a jellyfish tank?

 

[ISpeakForTheSeas]

Yes, Australia. Thanks for the help. Wonder how long they'll live in the tank - I like them

Ah, forgot to address this - if you want them to live longer, feed tiny planktonic critters like freshly hatched brine shrimp (Artemia) nauplii, rotifers, copepods, etc.; they feed on these kinds of critters in the wild.

Artemia nauplii seems to be the most important.

For the Pukia specimens:
"Captive specimens were maintained for months in pseudo-kreisels and modified box-kreisels, on a twice-daily feeding of newly-hatched Artemia nauplii enriched with Super Selco. As in the other forms with aborally-directed tentacle sheaths, P. falcata whirls to ingest its captured prey."*


For the Clytia specimens:
Medusa-stage:
"juveniles cannot efficiently catch live A. salina nauplii. This issue was mitigated by using the smaller nauplii of A. franciscana, which significantly improved the growth of baby medusae and shorted the time to adulthood."**

Polyp-stage:
"Another advantage of Clytia as a genetic model animal is the robustness of the polyp colony stage. A colony can rapidly extend stolons and generate new polyps in a vegetative manner. Commonly available Artemia nauplii are convenient and sufficient as food. Our tests showed that the colony size can double in less than 1 week, and that feeding once a day is sufficient, at least for wild-type strains."**

*Source:

https://www.researchgate.net/publication/242650791_Ctenophora_of_Australia

**Source:

An improved whole life cycle culture protocol for the hydrozoan genetic model Clytia hemisphaerica

The jellyfish species Clytia hemisphaerica (Cnidaria, Hydrozoa) has emerged as a new experimental model animal in the last decade. Favorable characteristics include a fully transparent body suitable for microscopy, daily gamete production and a relatively ...

www.ncbi.nlm.nih.gov

 

[ISpeakForTheSeas]

This fascinating. Maybe I should start a jellyfish tank?

They would be really cool for that - you need to do a special design for the Clytia, though; I suspect you could just put a fine mesh over the nylon retaining filters mentioned in a typical Kriesel tank, but I may be wrong:

"The measurements reported here revealed that the medusae grows to adult size and sexual maturity (about 10 mm in diameter) in less than 2 weeks, a time course suitable for genetic studies. The first few days, i.e. until the juvenile medusae reaches 2.5 mm bell diameter, were found to be critical for successful jellyfish growth for two reasons. Firstly, these small medusae cannot be accommodated in the Kreisel tanks as they pass through the nylon retaining filters. Closed tanks such as bubble-circulating nursery tanks or crystallizing dishes can be used for this stage, though they require additional attention to the water quality with overfeeding being particularly harmful. Alternative systems for the early step of medusa culture could be developed in the future, for instance, to avoid the harmful effect of air bubbles that can damage medusae as they reach larger sizes."*

*Source (same as the "**" source above):

An improved whole life cycle culture protocol for the hydrozoan genetic model Clytia hemisphaerica

The jellyfish species Clytia hemisphaerica (Cnidaria, Hydrozoa) has emerged as a new experimental model animal in the last decade. Favorable characteristics include a fully transparent body suitable for microscopy, daily gamete production and a relatively ...

www.ncbi.nlm.nih.gov

 

[WalkerLovesTheOcean]

The first one is likely a Clytia species hydromedusae - the species are indistinguishable without DNA evaluation during the medusa stage.

For image comparisons:

Hydrozoa - The World Hydrozoa Database - Clytia Lamouroux, 1812

www.marinespecies.org

Diario de f-sundw · iNaturalist Mexico

mexico.inaturalist.org

Development of the hydrozoan <i>Clytia gregaria</i>

This is Clytia gregaria , formerly known as Phialidium gregarium . The instructor of our Embryology class collected many adult individuals...

invert-embryo.blogspot.com

I'm fairly certain your specimens are Pukia falcata, as it seems to have the crescent-shaped tentacle bulbs (the two "y-shaped" white parts sticking off the central white white part); this would also make sense given that you're in Australia, where Pukia falcata is reportedly more common than Pleurobrachia (though this wasn't known until relatively recently).

https://www.researchgate.net/publication/242650791_Ctenophora_of_Australia

Ah, yes. It's definitely Pukia Falcata.

 

[betareef]

Ah, yes. It's definitely Pukia Falcata.

Fascinating to watch it drop it's two feeder tentacles and trail them along, then snap them up when some food is contacted.

Sadly they aren't going to do well in my fish tank with strong currents and filters.

 

[Slocke]

They would be really cool for that - you need to do a special design for the Clytia, though; I suspect you could just put a fine mesh over the nylon retaining filters mentioned in a typical Kriesel tank, but I may be wrong:

"The measurements reported here revealed that the medusae grows to adult size and sexual maturity (about 10 mm in diameter) in less than 2 weeks, a time course suitable for genetic studies. The first few days, i.e. until the juvenile medusae reaches 2.5 mm bell diameter, were found to be critical for successful jellyfish growth for two reasons. Firstly, these small medusae cannot be accommodated in the Kreisel tanks as they pass through the nylon retaining filters. Closed tanks such as bubble-circulating nursery tanks or crystallizing dishes can be used for this stage, though they require additional attention to the water quality with overfeeding being particularly harmful. Alternative systems for the early step of medusa culture could be developed in the future, for instance, to avoid the harmful effect of air bubbles that can damage medusae as they reach larger sizes."*

*Source (same as the "**" source above):

An improved whole life cycle culture protocol for the hydrozoan genetic model Clytia hemisphaerica

The jellyfish species Clytia hemisphaerica (Cnidaria, Hydrozoa) has emerged as a new experimental model animal in the last decade. Favorable characteristics include a fully transparent body suitable for microscopy, daily gamete production and a relatively ...

www.ncbi.nlm.nih.gov

I sent this to my friend who keeps and breeds jellyfish (or at least raises them from very small) and before she had a chance to say anything you had already said everything