Amphioctopus Marginatus (coconut or veined octopus) Taki, 1964

[DWhatley]

Description from Muctopus:

There are two color morphs described (and possibly more out there). One has distinct bright white sides of the suckers, and the funnel might not be very yellow. A. marginatus can have a transient blotch on the side that looks ocellus-like, but it's not well defined (more like a uniform purplish thumbprint), and it isn't visible all the time. The purple margins are sometimes not prominent as well. A. marginatus has fairly bumpy-looking skin, the tops of the bumps are pale or light purple, and the grooves in between are purple- this is because the skin is stretched over the bumps and chromatophore density lower (and higher in the grooves). Sometimes there is a dark purple triangle on each side of the eye (if I have time I'll post pics in the next few days). The lines on the arms are dark purple- when they show them- and run only from the base of the arm to the tips, right along the top edge of the suckers. If you have access to an academic library, look at the pics in "Field observations of mating in Octopus tetricus Gould, 1852 and Amphioctopus marginatus (Taki, 1964)(Cephalopoda: Octopodidae)". If not then PM me and I'll send you the pdf. Perhaps most notable about A. marginatus and other members of the genus is the distinctly short front arms (Arms I) and the very shallow front web (web A- the webbing between the two front arms). This group also has much shorter, thicker arms (usually appearing about 1.5-3 times as long as the mantle length, depending on the position) relative to the larger mantle as compared to A. aculeatus.

Amphioctopus marginatus (Taki, 1964) PDF from eolSpeciesLifedesks.org

 

[Thales]

Crissy - are there any particular photos of the A. marginatus I have that would be helpful? If so I can snap them and add them to this thread.

I have also noticed that the third right arm seems shorter and thicker in males.

 

[mucktopus]

Sure- always helpful! Also- I have a ton from the wild, just need to post...Ahh the 24 hr day...

 

[Thales]

D - do you want video in this thread?

 

[DWhatley]

Thales,
Sure, basically I am trying to push this unused area as an ID and behavioral section where the topic of each thread is the species. I am thinking about trying to keep each octo consolidated as one topic so that if you see the species your are interest in for information, official papers, videos, descriptions are all found together.

 

[DWhatley]

EMBRYONIC DEVELOPMENT OF AMPHIOCTOPUS MARGINATUS (TAKI) (MOLLUSCA: OCTOPODIDAE) IN CAPTIVITY
Sreeja, Anushma, K. and Biju Kumar 2013 (full pdf)

Abstract:
Octopuses, represented by over 300 species are the cephalopod molluscs inhabiting primarily tropical waters of the world. They are solitary invertebrates with little documentation of their response behaviour. Octopus is a dioecious animal with internal fertilization. The veined octopus Amphioctopus marginatus (Taki) is a mediumsized cephalopod reported to exhibit the unique behaviour of using coconut shells for making their homes and hence often referred to as the ‘coconut octopus’. Amphioctopus marginatus was collected from the Vizhinjam Bay in Thiruvananthapuram district of Kerala and acclimated to the aquarium conditions for recording their behaviour in captivity. The female specimen in captivity selected coconut shell for egg laying and performed parental care by continuously cleaning and aerating her eggs with her arms and by squirting jet of water over it. For the first time the embryonic development of the species was recorded in captivity. Developmental stages of the embryo was analysed based on the morphological characters. Development of chromatophores and its migration to various body parts and reduction in the size of the yolk sac was recorded stage by stage. Amphioctopus marginatus have planktonic hatchlings. The gestation period of the embryo was 17 -19 days at a temperature range of 28 - 300C and pH 7.8-8.1.

(dwhatley) Not much info in the paper but id does give a very simple description of what can be observed during development within the egg. The hatchlings were fed brine shrimp and died rapidly. It should be noted that the female died before the hatchlings emerged so water quality may have played a roll in the extremely short pelagic lifespan.

 

[DWhatley]

Collection, Transoport and Husbandry of the Coconut Octopus, Amphioctopus marginatus, from the Philippines
Bart Shepherd, Richard Ross, and Marisa Avila 2014 (full text)

The coconut octopus,
Amphioctopus marginatus
(Taki, 1964), is a small, charismatic,tropical, day-active species of octopus that is well suited for aquarium display.Despite this, they are never seen in the marine aquarium hobby and have never beendisplayed in public aquariums. As part of the California Academy of Sciences’long-term scientific collaboration in the Philippines, we collected 25 individuals of
A. mar- ginatus
on two occasions (May 2011 and November 2012) and transported a total of 18 coconut octopuses to SteinhartAquarium for research and display. We developedtechniques that support 100% survival of specimens during 3 critical stages: (1) col-lection via SCUBA, (2) temporary staging in the field and (3) international air-cargotransport. At Steinhart Aquarium, we successfully displayed
A. marginatus
in twoseparate exhibits. In aquaria, coconut octopuses lived their presumed natural lifes-pans (longevity up to 375 days post-collection, average of 195 days), exhibited typi-cal behaviors observed in the wild, such as constructing dens and hiding in contain-ers, and proved to be exceptionally popular with museum guests. The coconut octo-pus is a small-egged species with tiny paralarvae, complicating the development of aquarium-based captive breeding programs. In addition, commercial collectors haveproven to be an unreliable source for this species. Thus, for the time being, success-ful aquarium display programs will likely involve targeted collecting trips. ...

 

[DWhatley]

Sixteen-arm Tussle
Ned and Anna DeLoach 2020 rewrite of 2006 and 2008 experiences with Marginatus

While exploring the pumice plain of Lembeh Strait in northern Sulawesi, Indonesia, I watched a coconut roll down the steep sandy slope of Teluk Kembahu Bay. Even though much of the Strait’s mountainous terrain is fringed with copra plantations, and huskless shell halves commonly litter the seafloor, I had never seen an intact coconut underwater, much less one tumbling along the bottom. ...