This little crew look like scaffolding for death stars. My grandad did most of the early design work for the third one in the top row, during the war. It's made out of sealing wax, catgut and cocktails sticks.

428px-Haeckel_Acanthophracta.jpg
 
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zhao

there are no accidents
My grandad did most of the early design work for the third one in the top row, during the war. It's made out of sealing wax, catgut and cocktails sticks.

crazy! I've loved those "artforms in nature" books for ever. bought the expanded edition a few years ago. I thought they were just drawings? but I guess the drawings are based on models that people like your grandad made?
 

michael

Bring out the vacuum
Jesus, mention of the word isopod reminded me that they're the critters that eat the tongues from living fish and then live as replacement tongues, surviving on the food the fish try to eat.

Probably a different kind of isopod, but still. I've seen images of it before... maybe on here? I'll resist posting any pics of it anyway.

More giant isopod action:

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193IMG_0949-med.JPG


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Freakaholic

not just an addiction
Sharks can reproduce without sex.

The article (although there are some good pix at the link):


Captive shark had 'virgin birth'
Bonnethead (SPL)
The bonnethead is a species in the hammerhead group
Female hammerhead sharks can reproduce without having sex, scientists confirm.

The evidence comes from a shark at Henry Doorly Zoo in Nebraska which gave birth to a pup in 2001 despite having had no contact with a male.

Genetic tests by a team from Belfast, Nebraska and Florida prove conclusively the young animal possessed no paternal DNA, Biology Letters journal reports.

The type of reproduction exhibited had been seen before in bony fish but never in cartilaginous fish such as sharks.

Parthenogenesis, as this type of reproduction is known, occurs when an egg cell is triggered to develop as an embryo without the addition of any genetic material from a male sperm cell.

See how parthenogenesis takes place

The puzzle over the hammerhead birth was reported widely in 2001, but it is only with the emergence of new DNA profiling techniques that scientists have now been able to show irrefutably what happened.

The investigation of the birth was conducted by the research team from Queen's University Belfast, Nova Southeastern University in Florida, and Henry Doorly Zoo itself.

The scientists say the discovery raises important issues about shark conservation.

In the wild, these animals have come under extreme pressure through overfishing and many species have experienced sharp declines.

If dwindling shark groups resort to parthenogenesis to reproduce because females have difficulty finding mates, this is likely to weaken populations still further, the researchers warn.

The reason is that asexual reproduction reduces genetic diversity and this makes it harder for organisms to adapt - to changed environmental conditions or the emergence of a new disease, for example.

With normal sex, the mixing of maternal and paternal DNA introduces genetic novelty which can give animals new traits that might be advantageous in their new circumstances.

Sex marks

Dr Paulo Prodohl, a co-author on the Biology Letters paper from Queen's School of Biological Sciences, said: "Vertebrates in general have evolved away from parthenogenesis to boost genetic diversity and enhance evolutionary potential.

"The concern for sharks is that not only could we be reducing their numbers but we could be making them less fit as well."

"Our findings will now have to be taken into consideration for any conservation management strategy, especially for overexploited species."

The birth of the hammerhead (of the bonnethead species, Sphyrna tiburo) at Henry Doorly was as tragic as it was puzzling.

The new pup was soon killed by a stingray before keepers could remove it from its tank.

At the time, some theorised that a male tiger shark kept at the zoo could have been the father - but the institution's three bonnethead females had none of the bite marks that are usually inflicted on their gender during shark sex.

Some even suggested that one of the females could have had sex in the wild and stored the sperm in her body - but the three-year period in captivity made this explanation highly unlikely.

The new tests on the dead pup's tissues now show the newborn's DNA only matched up with one of the females - and there was none of any male origin.

Although extremely rare in vertebrates, parthenogenesis (out of the Greek for "virgin birth") occurs in a number of lower animals. Insects such as bees and ants use it to produce their drones, for example.
 

rewch

Well-known member
utterly rubbish footage of a fish-of-some-kind-that-is-not-a-coelocanth with spurious japanese voiceover, footage of divers going over the side (point of coelocanths is that they live in deep water i.e. below divable depths) & extra-spurious maps indicating madagascar (first discovered coelocanth pop[ulation) & an island off indonesia (next discovered coelocanth population)

i really don't feel that this thread should be debased with this sort of nonsense... & from a moderator, oh dear

[unable to spell, but:

Coelacanths are ovoviviparous

Coelacanths are the only living species known to have a functional intracranial joint, which almost completely separates the front and back halves of the skull internally]
 
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zhao

there are no accidents
the funny thing is that the only reason i know what a Coelacanth is is a Scelsi composition by that name. a beautiful, if i remember correctly, solo cello piece. i loved it so much and wanted to know what the name meant... but no, that doesn't look like one in the video. take it easy on suf, mods are fish too! (i.e. not perfect, nor necessarily holding degrees in marine biology)
 
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