Hapalochlaena (Blue Ring Octopuses)

tonmo

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tonmo

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Colin

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The Blue Ring is many things but I never really considered it as being the, 'Notorious sex pest of the animal world' :roflmao:

hehe
 

squidmaster

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:cthulhu: :cthulhu: :cthulhu: :cthulhu: :band: :heart: :snorkel: It seems it is a dangerous business to view such a mating process. I think I have observed some of the same fumbling in the human rhelm. Perhaps a longer foreplay is not that alARMIMG considering the female species of any animal seems to enjoy this ritual. :biggrin2: :biggrin2: :biggrin2: :biggrin2: 8) 8) 8)
I hope this is not too inkcredable to imagine this line of thinking, but I found the article rather humorous :lol: :lol: :lol: Sometimes I have mind pictures that go where no man has gone before :oops: :oops: :oops:
Thanks for the article I found it interesting :shock: :shock: :shock:
 

nanoteuthis

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Ummm -- why does this thread remind me of something Colin once posted about a typical Glasgow pub on Saturday night?

:lol:
 

Colin

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:oops: :oops: :oops: :oops: :oops: :oops:

yeah i seem to remember that, I was young free and single back then though..... em, I think....... something to do with squid beaks hehe

:lol:
 

tonmo

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Oktoputeao

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Yes friends, blue ring octopus. I know there exist 3 species:
H.fasciata ( my favourite)
H.lunalata
and H. maculosa

But yesterday I have seen another specie ( I can't find now the web page, sorry), it has the blue rings in a middle sice between H. lunalata and H.maculosa. What specie is it? there exist other species?

Cheers
Carles
 

Neogonodactylus

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H. nierstraszi, as far as I know, only exists as a preserved specimen from the Andaman Islands. There are several undescribed species. I have posted photos of one from Lizard Island and there is another very similar to H. lunulata in Lembeh. Norman also has photos of several undescribed species from Australia.

Roy
 

Feelers

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I thought (from my brief reading of Cephalopods of the World) that there were loads of species of Hapalochlaena making it very difficult to tell the difference , and they were just numbered 1-5(other than the ones mentioned). It looks like they have only very recently speciated- I wonder if they can interbreed at all?
 

DWhatley

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Microdistribution of tetrodotoxin in two species of blue-ringed octopuses (Hapalochlaena lunulata and Hapalochlaena fasciata) detected by fluorescent immunolabeling
Becky L. Williams, Michael R. Stark, Roy L. Caldwell (pdf) 2012

a b s t r a c t
Blue-ringed octopuses (genus Hapalochlaena) possess the potent neurotoxin tetrodotoxin (TTX). We examined the microdistribution of TTX in ten tissues of Hapalochlaena lunulata and Hapalochlaena fasciata by immunolabeling for fluorescent light microscopy (FLM). We visualized TTX throughout the posterior salivary gland, but the toxin was concentrated in cells lining the secretory tubules within the gland. Tetrodotoxin was present just beneath the epidermis of the integument (mantle and arms) and also concentrated in channels running through the dermis. This was suggestive of a TTX transport mechanism in the blood of the octopus, which would also explain the presence of the toxin in the blood-rich brachial hearts, gills, nephridia, and highly vascularized Needham’s sac (testes contents). We also present the first report of TTX in any cephalopod outside of the genus Hapalochlaena. A specimen of Octopus bocki from French Polynesia contained a small amount of TTX in the digestive gland.
I had to laugh at the reference to "octopamine", Looking it up (see link), it appears to have been named because it was first identified in the octopus and may have something to do with aggression.
 
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DWhatley

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Ontogeny of Tetrodotoxin Levels in Blue-ringed Octopuses: Maternal Investment and Apparent Independent Production in Offspring of Hapalochlaena lunulata
Becky L. Williams, Charles T. Hanifin, Edmund D. Brodie Jr., Roy L. Caldwell (subscription) 2011

Abstract
Many organisms provision offspring with antipredator chemicals. Adult blue-ringed octopuses (Hapalochlaena spp.) harbor tetrodotoxin (TTX), which may be produced by symbiotic bacteria. Regardless of the ultimate source, we find that females invest TTX into offspring and offspring TTX levels are significantly correlated with female TTX levels. Because diversion of TTX to offspring begins during the earliest stages of egg formation, when females are still actively foraging and looking for mates, females may face an evolutionary tradeoff between provisioning larger stores of TTX in eggs and retaining that TTX for their own defense and offense (venom). Given that total TTX levels appear to increase during development and that female TTX levels correlate with those of offspring, investment may be an active adaptive process. Even after eggs have been laid, TTX levels continue to increase, suggesting that offspring or their symbionts begin producing TTX independently. The maternal investment of TTX in offspring of Hapalochlaena spp. represents a rare examination of chemical defenses, excepting ink, in cephalopods
 

DWhatley

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#16
Science Friday Cephalopod Week Article 2014 June 25

This story is part of SciFri's #CephalopodWeek. For more on these marine animals, check out the videos here.

The venomous cephalopod above has a bit of a reputation—of 280 described octopus species, it’s probably one of the deadliest to humans. It contains a type of neurotoxin throughout its body called tetrodotoxin (the same as what’s found in puffer fish), which causes paralysis in bite victims by disrupting communication between nerves and muscles. Unable to breathe, a sufferer can die.

Yet, while this particular species—a type of blue-ringed octopus called Hapalochlaena fasciata—has caused one known death in Australia, where the animal is found, it's generally a pacifist. “They are dangerous, and people need to be educated about them, but they're not out hunting humans or trying to bite us," says Julian Finn, senior curator of marine invertebrates at the Museum Victoria in Melbourne. He would know: “I've observed hundreds of blue-ringed octopus underwater, and none of them have ever tried to attack me; they've all been going about their business.” (The victim who died, back in 1967, had taken the octopus out of the water, according to Finn.)

Also known as a blue-lined octopus (for the cobalt streaks on its body that match the rings on its arms), H. fasciata is one of four described blue-ringed octopus species. Based on specimens collected throughout the Indo-Pacific, however, there are probably 15 more species that have yet to be named, according to Finn, who has been studying the group for three years.

Although H. fasciata is common along Australia's eastern coast, casual swimmers tend to overlook it because it’s typically camouflaged to blend into its surroundings, according to Finn. Like its well-studied brethren, it only seems to reveal its cool coloring when it’s threatened or angry—and it does so by relaxing its muscles to expose structures called iridophores, which reflect blue-green light. To enhance the effect, the cephalopod darkens the skin surrounding the iridophores, resulting in a dazzling iridescent blue pattern that probably best translates to “back off.”
Yet, blue-ringed octopuses like H. fasciata don’t seem anxious to wield the toxic bite advertised by their colorful bark. When hunting, for instance, they appear to rely more on stealth to attack prey, such as crabs, rather than immediately subduing it with venom (injected by biting), according to Finn. “They tend to just grab prey that they can handle, and they can handle it really quickly, and there's no indication that they're using their venom,” he says.

Aside from its seeming reluctance to wield poison, H. fasciata has another quirk: Males don't appear capable of distinguishing between sexes. “You would think that an animal, with such amazing ability of color change, would convey [their sex] to the other members of their population, but they don't,” Finn says. Mating thus becomes a bit of a crapshoot, with males lusting after both sexes. “They just have no clue when it comes to spotting the girls,” says Finn.

The mating process is even more theatrical given the fact that males also have a physical handicap, so to speak. In octopus species, males have a modified arm that they use to deliver a packet of sperm into a female’s oviducts, which are located in a space in her sack-like body called the mantle cavity (“essentially, he hands [the sperm] to her,” says Finn). In the well-studied blue-ringed octopus species, that reproductive arm is shorter than the other arms, which means that a male needs to grab onto a female in order to successfully insert the sperm. As a result, if a male H. fasciata mistakenly latches onto another male, “it’s not until he’s actually got his reproductive arm inside the mantle cavity [that] he goes, ‘Oop! Sorry—you're a bloke!’” says Finn. He then lets go of the embrace and keeps on trying until he gets it right.

The inability to discern among sexes has been observed in another species of blue-ringed octopus in an aquarium setting, but Finn has witnessed the behavior firsthand among H. fasciata in the wild. “They must have greater success just by grabbing every other blue-ringed octopus that goes past as opposed to wasting time trying to distinguish,” he says. “It must be working for them.”
 

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#17
Mating behaviour and postcopulatory fertilization patterns in the southern blue-ringed octopus, Hapalochlaena maculosa
Peter Morse, Christine L. Huffard, Mark G. Meekan, Mark I. Mccormick Kyall R. Zenger 2017 (Science Direct subscription)
Female octopuses are known to store sperm from multiple males they encounter throughout a breeding season, before laying a single clutch with mixed paternity. Although octopuses display a broad range of precopulatory behaviours, and both sperm competition and cryptic female choice have been hypothesized to occur, the current understanding of how these processes influence resulting paternity remains limited. This study aimed to identify behavioural factors associated with paternity patterns and the capacity of females to bias paternity postcopulation to specific males in the southern blue-ringed octopus, Hapalochlaena maculosa. Genetic markers and controlled, sequential, laboratory pairings of genotyped individuals were used to examine paternity patterns and compare them to relative signatures of male sperm remaining in female oviducal glands after egg laying. Multiple paternity was discovered in all 12 laboratory-reared clutches. There was no indication that the relative time spent in copulation affected the resulting paternity. Males that waited for females to terminate the copulation had greater paternity when they were the first candidate male, but this was not the case among second candidate males. The relative quantities of candidate male alleles detected in female oviducal glands after egg laying were consistent with relative paternity of the candidate males in all but three cases. In one of these, sibship analysis revealed that the male that obtained less paternity than expected was in fact the female's full-sibling brother. Although this study found no evidence for female postcopulatory selection of male sperm, anecdotal evidence suggests that female H. maculosa might benefit from polyandry if chemical processes can favour clutch fertilization by unrelated males. Future studies, investigating paternity bias among genotyped males of varying, but known relatedness to the female, might help to validate this pattern.
 

tonmo

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DWhatley

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Genome-wide comparisons reveal a clinal species pattern within a holobenthic octopod—the Australian Southern blue-ringed octopus, Hapalochlaena maculosa (Cephalopoda: Octopodidae)
Peter Morse, Shannon R. Kjeldsen, Mark G. Meekan, Mark I. Mccormick, Julian K. Finn, Christine L. Huffard, Kyall R. Zenge 2018 (Wiley Online, Ecology and Evolution Open access)

Abstract
The southern blue-ringed octopus, Hapalochlaena maculosa (Hoyle, 1883) lacks a planktonic dispersal phase, yet ranges across Australia's southern coastline. This species’ brief and holobenthic life history suggests gene flow might be limited, leaving distant populations prone to strong genetic divergence. This study used 17,523 genome-wide SNP loci to investigate genetic structuring and local adaptation patterns of H. maculosaamong eight sampling sites along its reported range. Within sites, interrelatedness was very high, consistent with the limited dispersal of this taxon. However, inbreeding coefficients were proportionally lower among sites where substructuring was not detected, suggesting H. maculosa might possess a mechanism for inbreeding avoidance. Genetic divergence was extremely high among all sites, with the greatest divergence observed between both ends of the distribution, Fremantle, WA, and Stanley, TAS. Genetic distances closely followed an isolation by geographic distance pattern. Outlier analyses revealed distinct selection signatures at all sites, with the strongest divergence reported between Fremantle and the other Western Australian sites. Phylogenetic reconstructions using the described sister taxon H. fasciata (Hoyle, 1886) further supported that the genetic divergence between distal H. maculosa sites in this study was equivalent to that of between established heterospecifics within this genus. However, it is advocated that taxonomic delineations within this species should be made with caution. These data indicate that H. maculosa forms a clinal species pattern across its geographic range, with gene flow present through allele sharing between adjacent populations. Morphological investigations are recommended for a robust resolution of the taxonomic identity and ecotype boundaries of this species.
 

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