Macroctopus

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Macroctopus
Maori Octopus-Octopus maorum (8378473607).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae
Genus: Macroctopus
Robson, 1928
Species:
M. maorum
Binomial name
Macroctopus maorum
(Hutton, 1880) [1]
Synonyms [1]
  • Octopus communisPark, 1885
  • Octopus flindersi Cotton, 1932
  • Octopus maorumHutton, 1880

Macroctopus maorum is known more commonly as the Maori octopus or the New Zealand octopus (wheke in Maori). It is found in the waters around New Zealand and southern Australia. [1] [2] M. maorum is one of the largest and most aggressive octopus species living in the New Zealand and Australian waters. They feed mainly on crustaceans and fish. Although they have a short life span, the females lay thousands of eggs and are very protective of them.

Contents

Identification

Macroctopus maorum is a large octopus and it is regularly described as a ‘robust’ species, it is a member of the Octopus macropus species complex. The morphological traits characteristic of this complex are a high number of gill lamellae, a robust conical copulatory organ and arms of varying length with long unequal dorsal arms generally four to six times longer than the mantle. Although being unequal, their arms are said to be long and evenly tapering and Macroctopus maorum are even known to regrow arms when one has been lost. [2] Being the largest member of its complex arm span is said to exceed 3 metres (9.8 ft). [3] They have four to six suckers on the first and second arm pairs which are usually about 40 millimetres (1.6 in) in size. Suckers are arranged in two rows down the arm length. There is thought to be no correlation between sexes and size of suckers; however, there was an increase in sucker size with body mass increase. [2] Coloration of this species can vary Macroctopus maorum can be distinguished from other species by the colour, they will be either orange-brown or dark purple-grey. The octopus has numerous small iridescent white spots on the web, arms and dorsal arm crown but there are no spots present on the mantle. [2] Macroctopus maorum has 12–14 gill lamella per demibranch, the mantle is described as broadly ovoid and exhibits a skin pattern of longitudinal ridges. Along the dorsum there are five rows of unbranched papillae and two more papillae appear individually above the eyes. Octopus papillae are camouflage specialised with the ability to change shape, such as by extending in and out from the body. [4] Male M. maorum have a small ligula, the ligula is a specialised arm tip on the hectocotylized arm which grips to allow the transfer of spermatophores. Within the complex O. macropus, Macroctopus maorum is thought to be the largest member. In a study estimating M. maorum size based on a sample of 90 beaks, the largest individual found had a body length of 2.0 metres (6 ft 7 in) and body mass of 12 kilograms (26 lb). Macroctopus maorum has an upper beak and lower beak, the upper beak can be used to differentiate Macroctopus maorum and Enteroctpus zealandicus as it has a lack of overlap in the ratio of upper hood length and upper chest length. Macroctopus maorum hatchlings are usually about 5.06 millimetres (0.199 in) in size, they have 7–8 suckers per arm and each dorsal arm will have 6–11 chromatophores. [2]

Life cycle/Phenology

Sexual maturity

Female

[5] assigned 5 maturity stages for the egg development of Macroctopus maorum:

  1. Newly formed primary oogonia which has a small, distinct nucleus is visible and Follucular cells attach to the ovum and forming follicular epithelium.
  2. Follicular epithelium has completely filled the ova and nucleus is no longer visible. There are no yolk present and cuboidal follicular cells become distinct and closely packed.
  3. First granular yolk appears in the ova. Epithelial convolution still occupying much of the interval volume.
  4. Only periphery of the ova found and been forced out by the expanding yolk. Nuclei of epithelium has now become indistinct.
  5. Mature ova which have thin walls and are replete with yolk. Follicular epithelium produced the chorion and degenerated. Ova is free in the ovary, oviduct or oviducal glands.

Female that undergoes stage 4 oocytes were caught throughout the month of April to October, while those females that undergo stage 3 were caught only in April and July. However, females with stage 5 oocytes were caught every month except May and August. [5]

Male

In the male, the position of testis from juvenile to adult is different. [6] The position of testis moved backward until it reached the final position at the hinder end of the body during the adult stage. [6] Fully mature male octopus consist of fully-formed spermatophores in the Needham’s sac. [5] They usually had up to 13 spermatophores in the Needham’s sac. Furthermore, their reproductive organ will increase in size over the lifetime.

Mating

During mating, the male Macroctopus maorum will be on top pinning down the female and usually overpowering the female physically or pouncing on them. [2] The male will inserts a sperm packet by passing it along the arms to the oviduct of the female. [2] When it get near to the oviduct, the end of the spermatophore burst open and released the sperm. [7] Male octopus will then become senescent and die after mating. [7] Female "Macroctopus maorum mature and mate during March and October. [5]

Eggs laying, brooding and hatching

Macroctopus maorum construct the posterior mantle to push out the eggs during egg laying. [2] The female usually will stop eating for 2 weeks during the laying eggs period and continue to look after the eggs until they hatched. [2] Macroctopus maorum usually lay approximate 7000 eggs. [2] Their eggs are usually clusters of 3-12 eggs and cemented directly to the substratum. [8] Octopus maorum swept across the eggs sheet with one or more tentacles to keep the eggs well oxygenated, clean and safe from predators. [8] During brooding period female Macroctopus maorum will stop feeding so that it produce less wastes and ensure the water quality is good for the eggs. [7] When the eggs are about to hatch Macroctopus maorum will frequently squirt water on the eggs using siphon until the eggs hatched. [8] After the eggs hatch, the female Macroctopus maorum will swim away and might die as she has been weakened from guarding the eggs. The hatchlings are planktonic and have 7 to 8 suckers per arm. [2] If the hatchling manages to survive, the life cycle will be repeated.

Global distribution and habitat

Global distribution

M. maorum is commonly found in the waters of New Zealand and South Australia, [2] preferring temperate to sub-antarctic waters. [2] In New Zealand they are found off the coasts of both the North and South islands, [4] and is one of the most common species of octopus in the country. [9] M. maorum is also common in the waters of the islands surrounding New Zealand including Campbell, Chatham and Auckland islands. [4] In Southeast Tasmania, at Eaglehawk Bay the site of a commercial fishery is the only known inshore location where the M. maorum have been known to gather in large numbers year round. [10]

Habitat

M. maorum lives in the benthic zone in soft-sediment and rubble habitats with depths of 0–549 metres (0–1,801 ft) [5] and will sometimes forage in nearby hard-reef habitats and are less common at the fringes between reefal and soft sediment habitats. [2] Rather than settling in a specific location, M. maorum uses temporary shelters. [2] In Tasmania, young M. maorum have been observed settling in intertidal rock pools. [4] Similar sightings of M. maorum in intertidal rock pools have been reported during the summer months in Kaikoura and Banks Peninsula. [11]

Diet/Prey/Predators

Diet and Foraging

A study of M. maorum off the coast of southeastern Tasmania found evidence of 12 different species in the stomachs of sampled octopuses with the dominant prey being the crab P. gaimardii and other M. maorum. [10] This is a low number of prey species compared to other species of octopus and it is assumed that the diet of M. maorum in Southeastern Tasmania is more diverse than results indicated in the study. [10] M. Maorum will eat bivalves, crustaceans and fish but are selective and show preference to lobster, crabs and scallops. [2] As is the case with other octopus species, M. maorum injects prey with a toxin that slowly liquefies flesh so that it can be more easily digested. [2] Cannibalism is a common behavior for many species of octopus in the order of large eating small, however small M. maorum are known to attack larger octopus particularly Octopus tetricus where habitats overlap. [2] M. maorum feeds mainly at night unless food is scarce in which case it must forage during the day. [2] M. maorum is an extremely evolved hunter with a range of hunting methods including stalking, ambush, jet-propulsion and digging. [11] When executing different hunting methods colour and texture are adjusted, often by darkening and erection of papillae. [11] Prey such as crabs are pounced on using the speed of jet propulsion and prey is trapped under the octopus’s web in what is appropriately called the parachute position. [11] Alternatively, in a situation where prey is nearby the octopus will simply snatch it with one of its tentacles. In the case of prey escaping and hiding M. maorum will persistently dig to uncover prey by pushing material into its web and dumping the removed material by the entrance to its home. [11]

Predators and parasites

Macroctopus maorum is preyed upon by fur seals, sea lions, pilot whales, other octopus and the northern royal albatross. [3] Penguins such as yellow-eyed, fiordland crested and little blue penguin might prey on Macroctopus maorum as well. [12] M. maorum hosts dicyemid mesozoans and digenetic trematodes as parasites. [4] A more recent study of the species adds wobbegongs, school and gummy sharks, mulloway, queen snapper and dolphins to the list of predators. [13] Sea slugs will often feed on M. maorum eggs. [6]

Other information

While research was being carried out the behavior of M. maorum was monitored and results showed that while being in the aquarium they showed a variety of behaviors such as fighting, flamboyant postures and defensive up-turning of arms, withdrawing and cleaning. Small M. maorum would often take on larger octopuses such as O. tetricus such as a 300 grams (11 oz)M. maorum fought and started to eat a 1 kg O. tetricus. [2] M. maorum will generally reach a weight of up to 12 kilograms (26 lb) when fully grown. They live solitarily in a den for up to three months at a time. They would gather prey remains to form a midden (piles of shells, bones and rocks) the midden is used to conceal the entrance to their den. Sometimes mature M. maorum have been located in Eaglehawk Bay in Tasmania nobody knows why they aggregate here or where they come from. [14] M. maorum has a significant economic effect on rock lobster fisheries in New Zealand and Southern Australia. M. maorum will prey on trapped southern rock lobster killing many and leaving some lobster missing limbs making them unsaleable. [15] This also means that M. maorum is being caught as bycatch. The South Australian rock lobster fisheries report that since 1983 octopus bycatch has ranged from 38,000 to 119,000 octopus a year. [16] M. maorum are fished commercially in Eaglehawk Bay Tasmania where they congregate throughout the year in large numbers (as many as 70 octopuses). [5] Eaglehawk Bay is the sole location where such a large inshore congregation is known to occur. [5] M. maorum had been used as a model to determine the age of merobenthic, by using stylet increment analysis. [14] SIA (Stylet Increment Analysis) is a method which was developed recently to determine the age of an octopus, age is important for estimating the growth rate, population age structure, mortality rate, productivity and processes. Due to this understanding, it can be used to make important decisions surrounding fisheries and conservation management. Stylets are highly reduced internal shells that consist of small rod-like structures, the result of SIA showed that a stylet of M. maorum can be hard to prepare and age. However, SIA can only provide the relative age of the species, due to lack of knowledge surrounding the formation of the first stylet increment. Therefore, alternative methods of age determination of the octopus may need to be explored. [17]

Related Research Articles

<span class="mw-page-title-main">Octopus</span> Soft-bodied eight-limbed order of molluscs

An octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates.

<span class="mw-page-title-main">Squid</span> Superorder of cephalopod molluscs

A squid is a mollusc with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.

<span class="mw-page-title-main">Glass octopus</span> Species of octopus

Vitreledonella richardi, also known as the glass octopus, is an incirrate octopus. It is in the genus Vitreledonella and of the family Amphitretidae.

<i>Jasus edwardsii</i> Species of crustacean

Jasus edwardsii, the southern rock lobster, red rock lobster, or spiny rock lobster, is a species of spiny lobster found throughout coastal waters of southern Australia and New Zealand including the Chatham Islands. It is commonly called crayfish in Australia and New Zealand and kōura in Māori. They resemble lobsters, but lack the large characteristic pincers on the first pair of walking legs.

<i>Euprymna tasmanica</i> Species of mollusc

Euprymna tasmanica, also known as the southern dumpling squid or southern bobtail squid, is a bobtail squid that lives in the shallow temperate coastal waters of southern Australia's continental shelf. It lives for between 5 and 8 months and the adults can grow up to 6 or 7 cm long with a mantle length of 3 to 4 cm. They are found in seagrass beds or areas with soft silty or muddy bottoms from Brisbane on the east coast to Shark Bay on the west, as well as around Tasmania. Southern dumpling squid are nocturnal and during the day hide in sand or mud covered in a mucus-lined coat of sediment. If disturbed acid glans can quickly remove this coat as an additional decoy to ink squirting.

<i>Doryteuthis opalescens</i> Species of Cephalopoda

Doryteuthis opalescens, the opalescent inshore squid or market squid, is a small squid in the family Loliginidae. It is a myopsid squid, which is the near shore group and that means that they have corneas over their eyes. The species lives in the eastern Pacific Ocean from Mexico's Baja California peninsula to Alaska, United States, and as an inshore squid it can be found with a range of 200 miles (320 km) off the coast.

<span class="mw-page-title-main">Giant Pacific octopus</span> Species of cephalopod

The giant Pacific octopus, also known as the North Pacific giant octopus, is a large marine cephalopod belonging to the genus Enteroctopus and Enteroctopodidae family. Its spatial distribution encompasses much of the coastal North Pacific, from the Mexican state of Baja California, north along the United States' West Coast, and British Columbia, Canada; across the northern Pacific to the Russian Far East, south to the East China Sea, the Yellow Sea, the Sea of Japan, Japan's Pacific east coast, and around the Korean Peninsula. It can be found from the intertidal zone down to 2,000 m (6,600 ft), and is best-adapted to colder, oxygen- and nutrient-rich waters. It is one of the largest octopus species on earth and can often be found in aquariums and research facilities in addition to the ocean. E. dofleini play an important role in maintaining the health and biodiversity of deep sea ecosystems, cognitive research, and the fishing industry.

<i>Metasepia pfefferi</i> Species of cuttlefish

Metasepia pfefferi, also known as the flamboyant cuttlefish, is a species of cuttlefish occurring in tropical Indo-Pacific waters off northern Australia, southern New Guinea, as well as numerous islands of the Philippines, Indonesia and Malaysia.

<i>Nototodarus sloanii</i> Species of mollusc

Nototodarus sloanii is a species of squid commonly known as the New Zealand arrow squid or Wellington flying squid. It is also known by its Māori name of wheketere. It is a favoured prey species of a number of marine mammals and diving birds. It is an important food source for the New Zealand fur seal and two endangered species: the New Zealand sea lion and the yellow-eyed penguin. N. sloanii is sought by trawler fishermen for human consumption; New Zealand sea lions are frequently caught in trawl nets and drowned when feeding on N. sloanii.

<i>Vulcanoctopus hydrothermalis</i> Species of benthic octopus

Vulcanoctopus hydrothermalis, also known as the vent octopus, is a small benthic octopus endemic to hydrothermal vents. Notably, It is the only known species of the genus Vulcanoctopus. This vent octopus is endemic to the hydrothermal vent habitat that is located in the East Pacific Rise.

<span class="mw-page-title-main">Cephalopod beak</span> Body part of cephalopods

All extant cephalopods have a two-part beak, or rostrum, situated in the buccal mass and surrounded by the muscular head appendages. The dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion. The beak may also be referred to as the mandibles or jaws. These beaks are different from bird beaks because it crushes bone while most birds don't.

<i>Illex coindetii</i> Species of squid

Illex coindetii, commonly known as the southern shortfin squid or broadtail shortfin squid, is a species of neritic squids in the family Ommastrephidae. They are found in the Mediterranean Sea and on both sides of the north Atlantic Ocean.

Eledone massyae, the combed octopus, is a small benthic octopus found off the Atlantic coasts of southern South America, particularly Argentina and southern Brazil.

Octopus chierchiae is commonly known as the lesser Pacific striped octopus or pygmy zebra octopus. It has been proposed as a model organism for cephalopod research as it is one of the few octopus species with the ability to lay multiple egg clutches (iteroparity), compared to most octopus species that are semelparous and die after one reproductive event. This makes Octopus chierchiae a candidate for sustainable and multigenerational laboratory research.

<i>Octopus tetricus</i> Species of mollusc

Octopus tetricus, the gloomy octopus or the common Sydney octopus, is a species of octopus from the subtropical waters of eastern Australia and New Zealand. O.tetricus belongs to the Octopus vulgaris species group and is a commercially prized species. All species within the O. vulgaris group are similar in morphology. The English translation of O. tetricus (Latin) is 'the gloomy octopus'.

<i>Pinnoctopus cordiformis</i> Species of mollusc

Pinnoctopus cordiformis is a species of octopus found around the coasts of New Zealand. It is one of the most common species of octopus in the country.

<span class="mw-page-title-main">Antarctic flying squid</span> Species of squid

The Antarctic flying squid is a species of squid from the subfamily Todarodinae of the family Ommastrephidae, a family of pelagic squid from the order Oegopsida. It has a circumglobal distribution in the seas around the lower latitudes of the Southern Ocean.

<i>Wunderpus photogenicus</i> Species of cephalopod

Wunderpus photogenicus, the wunderpus octopus, is a small-bodied species of octopus with distinct white and rusty brown coloration. 'Wunderpus' from German “wunder” meaning ‘marvel or wonder’.

<i>Octopus bimaculatus</i> Species of octopus

Octopus bimaculatus, commonly referred to as Verill's two-spot octopus, is a similar species to the Octopus bimaculoides, a species it is often mistaken for. The two can be distinguished by the difference in the blue and black chain-like pattern of the ocelli. O. bimaculatus hunt and feed on a diverse number of benthic organisms that also reside off the coast of Southern California. Once the octopus reaches sexual maturity, it shortly dies after mating, which is approximately 12–18 months after hatching. Embryonic development tends to be rapid due to this short lifespan of these organisms.

<i>Octopus insularis</i> Species of octopus

Octopus insularis is a species of octopus described in 2008 from individuals found off the coast of Brazil, with a potentially much larger range.

References

  1. 1 2 3 Julian Finn (2017). "Macroctopus maorum (Hutton, 1880)". World Register of Marine Species. Flanders Marine Institute. Retrieved 4 February 2018.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 T. J. Anderson (1999). "Morphology and biology of Octopus maorum Hutton 1880 in northern New Zealand". Bulletin of Marine Science . 65 (3): 657–676.
  3. 1 2 Lalas, C (2009). "Estimates of size for the large octopus Macroctopus maorum from measures of beaks in prey remains". New Zealand Journal of Marine and Freshwater Research. 43 (2): 635–642. doi: 10.1080/00288330909510029 .
  4. 1 2 3 4 5 Stranks, T. N. (1998). Systematics of the family Octopodidae (Mollusca:Cephalopoda) of South-Eastern Australia. (Masters Research thesis, Dept. of Zoology, The University of Melbourne)
  5. 1 2 3 4 5 6 7 Grubert, M. A.; Wadley, V. A. (2000). "Sexual Maturity and Fecundity of Octopus Maorum in Southeast Tasmania". Bulletin of Marine Science. 66 (1): 131–142.
  6. 1 2 3 Benham, W. B. (1943). "The Octopodos Mollusca of New Zealand. (III). The Giant Octopus, Macroctopus maorum (Hutton):in Youth, Adolescence and Maturity". Transactions of the Royal Society of New Zealand. 73: 139–152.
  7. 1 2 3 . Mather, J. A., Anderson, R. C. & Wood, J.B. (2010) Octopus: The Ocean’s Intelligent Invertebrate. Timber Press
  8. 1 2 3 Batham, E. J. (1957). "Care of Eggs by Octopus Maorum ". Transactions of the Royal Society of New Zealand. 84 (3): 629–638.
  9. ↑ Vennell, Robert (5 October 2022). Secrets of the Sea: The Story of New Zealand's Native Sea Creatures. HarperCollins Publishers Ltd. pp. 118–125. ISBN   978-1-77554-179-0. Wikidata   Q114871191.
  10. 1 2 3 Grubert, Mark A., Wadley, Vicki A., White, Robert W. G. (1999) Diet and feeding strategy of Octopus maorum in southeast Tasmania, Bulletin of Marine Science, 65(2), 441-451. University of Miami - Rosenstiel School of Marine and Atmospheric Science
  11. 1 2 3 4 5 Pack, Y. (1982) Masking behaviour and related biology of Notomithrax ursus (Oxyrhyncha: Majidae) (Doctoral Thesis, University of Canterbury, Christchurch, New Zealand). Retrieved from http://ir.canterbury.ac.nz/handle/10092/5947
  12. ↑ Heezik, Y. V. (1990). "Diets of Yellow-eyed, Fiordland crested, and Little Blue Penguins Breeding Sympatrically on Codfish Island, New Zealand". New Zealand Journal of Zoology. 17 (4): 543–548. doi: 10.1080/03014223.1990.10422952 .
  13. ↑ Shepard, S., & Edgar, G. (2013). Maori octopus Macroctopum maorum and pale octopus Octopus pallidus. In Ecology of Australian Temperate Reefs: The Unique South (pp. 138–130). Collingwood Australia: Csiro Publishing
  14. 1 2 Doubleday, Z. A.; Danyushevsky, L.; Pecl, G. T.; Semmens, J. M. (2008). "Using stylet elemental signatures to determine the population structure of Octopus maorum". Marine Ecology Progress Series. 360: 125–133. Bibcode:2008MEPS..360..125D. doi: 10.3354/meps07389 .
  15. ↑ Harrington, J. J.; Semmens, J. M.; Gardner, C.; Frusher, S. D. (2006). "Predation of trap-caught southern rock lobsters, Jasus edwardsii (Hutton, 1875), in Tasmanian waters by the Maori octopus, Octopus maorum (Hutton, 1880): Spatial and temporal trends". Fisheries Research. 77: 10–16. doi:10.1016/j.fishres.2005.09.003.
  16. ↑ Brock, D. J.; Ward, T. M. (2004). "Maori octopus (Octopus maorum) bycatch and southern rock lobster (Jasus edwardsii) mortality in the South Australian rock lobster fishery". Fishery Bulletin.
  17. ↑ Doubleday, Z. A.; White, J.; Pecl, G.T.; Semmens, J. M. (2011). "Age determination in merobenthic octopuses using stylet increment analysis: assessing future challenges using Macroctopus maorum as a model". Journal of Marine Science. 68 (10): 2059–2063. doi: 10.1093/icesjms/fsr135 .
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