38 — Anemones and amphipods at Piha

Gammaridean amphipods swarm around a
giant shore anemone, Lion Rock, Piha.

Gammaridean amphipods swarm around a
giant shore anemone, Lion Rock, Piha.

These videos are of the giant shore anemone (Oulactis magna) at Piha. Often these anemones are in rock pools teaming with small shrimp-like animals called amphipods. Most people encounter amphipods when they turn over seaweed on the beach; the jumping sandhoppers, which appear from under the seaweed are a kind of amphipod.

Amphipods are very diverse, but come in three main flavours: Gammaridea, Hyperiidea, and Senticaudata (there's also the Ingolfiellidea, but they are not as common as the the other three major suborders). At the moment there are thought to be about 9500 species, and this number is probably going to increase.

As a group, amphipods are very important in marine food webs, as nearly everything larger eats them, e.g., Jones (2008); Padovani et al., (2012). However, I'm not sure that these anemones actually eat these particular amphipods, but I did see some small ones get caught by the tentacles of one anemone, so maybe...


More info:

https://en.wikipedia.org/wiki/Amphipoda

Horton, T., Lowry, J., De Broyer, C., Bellan-Santini, D., Coleman, C. O., Daneliya, M., Dauvin, J-C., Fišer, C., et al., & Zeidler, W. (2016). World Amphipoda Database. Accessed at http://www.marinespecies.org/amphipoda on 2016-09-30

37 — Octopus

This is the same species of octopus I posted earlier in this blog, but this video was taken last year. This particular octopus was among the  rocks beside Pilot Wharf, Mt. Maunganui and did some interesting colour changes.

This video next is really cool. It was taken earlier this year at Piha, west coast of Auckland. As far as I can tell, it's the same species of octopus. I was taking pictures of small invertebrates in seaweed at a place called the Blue Pool, at south piha with I felt something brush my leg. I jumped, as I thought it might be a crab. But when I looked down there was nothing there. I carried on taking pictures and then it happened again, I looked down, but there was nothing again. The third time I looked, I saw this long tentacle reaching out from under an overhanging ledge in the pool; uncoiling, just far enough to touch my foot.

Then, I pointed the camera under the ledge and captured this piece of video. Literally, I couldn't see what I was filming, so I was very pleasantly surprised to get video the octopus catching and eating a paddle crab. I  think it's really interesting how the octopus immobilises the crabs claws (Its only defensive weapons) early on...

36 — Green anemone, Aulactinia veratra

Green anemone, Long Bay
Marine Reserve, 24/3/17.

Green anemone, Long Bay
Marine Reserve, 24/3/17.

Green anemone, Long Bay
Marine Reserve, 24/3/17.

The green anemone, Aulactinia veratra * is found throughout New Zealand; at least as far south as Dunedin and throughout southern Australia, and Queensland. It's main distinguishing characteristic is the lime-green colour of the tentacles. However, when it comes to invertebrates colour is a very unreliable diagnostic feature. low-tidal rock pools at Long Bay marine reserve.

Ecologically, I've not been able to find out very much about green anemones. They appear to be more common in Australia, but that's about it.

* (Drayton in Dana, 1846)




















More info:

https://shapeandtheidea.wordpress.com/2015/11/07/green-anemone-aulactinia-veratra-drayton-in-dana-1846/

35 — Black nerita, Nerita (Lisanerita) melanotragus

Nerita (Lisanerita) melanotragus,
Pilot Bay, 27/9/16

Nerita (Lisanerita) melanotragus,
Pilot Bay, 27/9/16

These are black neritas, Nerita (Lisanerita) melanotragus *. They are very common in the north of New Zealand in a variety of habitats, from exposed coasts to mangrove forests, but aren't found much south of Cook Strait. Neritas are mostly tropical and there are far more species found in those warmer waters.

They are also quite interesting because their distribution is clumped. That is to say, they seem to like hanging out together, while you commonly see isolated individuals, you also see them tightly grouped together.

There have been a few reasons put forward to try and explain why they might clump together in this way. One reason is to avoid dehydration. Clumped together they increase the surface area around them, so water doesn't evaporate as quickly. Also, by being a in a group like this, the ones in the middle have some protection from predation. For example I've seen the large black rock shell Haustrum haustorium (Gmelin, 1791) attempting to bore into a large solitary nerita. Also, one other reason could be to find a breeding partner: it's presumably a lot easier to do this if you're surrounded by your own species.

* E.A. Smith, 1884

More info:

https://www.ncbi.nlm.nih.gov/pubmed/16029478

https://en.wikipedia.org/wiki/Nerita_melanotragus

34 — Wandering anemone, Phlyctenactis tuberculosa

Wandering anemone (P. tuberculosa),
Mt. Maunganui, 23/9/16.

Wandering anemone (P. tuberculosa),
 Mt. Maunganui, 23/9/16.

Wandering anemone (P. tuberculosa),
 Mt. Maunganui, 23/9/16.

The wandering anemone, Phlyctenactis tuberculosa * can get quite big: upwards of 15 cm. They are found in New Zealand, southern Australia, and Chile.

They attach to seaweeds and/or rocks, and as their name suggests can move around if conditions are better elsewhere. Structurally they're quite flaccid and generally squishy.

These examples were found around the side of the Mount, past the Mount Beach, where the water starts to become cleaner. These were mostly attached to the flapjack Carpophyllum maschalocarpum. Being attached to seaweed, they move around a lot in the swell, so they can be quite hard to photograph.

* (Quoy & Gaimard, 1833)























More info:

https://shapeandtheidea.wordpress.com/2015/10/11/wandering-anemone/

http://taputeranga.org.nz/the-marine-life/invertebrates/wandering-anemone-2/

33 — Oulactis muscosa

Oulactis muscosa, Pilot Bay,
Mt. Maunganui, 23/9/16.

Speckled camouflage anemone Oulactis muscosa * Pilot Bay, Mt. Maunganui. They like similar habitat to the closely related giant shore anemone (O. magna), but they prefer calmer, more sheltered waters.

* (Drayton in Dana, 1846)



























































More info: 

https://shapeandtheidea.wordpress.com/2015/10/14/speckled-anemone/

31 — Oulactis magna

Oulactis magna, Stuckey, 1909), from
Moturiki Island, 23/9/16.

Oulactis magna, Stuckey, 1909), from
Moturiki Island, 23/9/16.

Oulactis magna, Stuckey, 1909), from
Moturiki Island, 23/9/16.

These are giant shore anemones (Oulactis magna, Stuckey, 1909), from Moturiki Island, Mt. Maunganui.

30 — Macroctopus maorum

Macroctopus maorum, Pilot bay Wharf,
Mt. Maunganui, 21/9/16

Macroctopus maorum, Pilot bay Wharf,
Mt. Maunganui, 21/9/16

Macroctopus maorum, Pilot bay Wharf,
Mt. Maunganui, 21/9/16

Macroctopus maorum, Pilot bay Wharf,
Mt. Maunganui, 21/9/16

I was having a look around the base of Mt. Maunganui (as there was a really low tide) and came across an octopus (Macroctopus maorum).

Octopuses are masters of colour change and if you look through the following pictures you can see that this octopus changes colour more than once.











































More info:

https://www.google.co.nz/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=octopus+tetricus

29 — Not the hydroids you are looking for #15

Thecate hydroids, Ngapipi Bridge 20/8/16

Not the hydroids you are looking for #15.

If you look closely you can see the individual polyps along each branch of the colony.

Athecate hydroids, Ngapipi Bridge, 20/9/16

The next picture shows an athecate hydroid colony. On each branch you can see each polyp as a small bud-like structure sticking up from the branch. In order to identify these animals to species it's necessary to cut bits off and look at them under a microscope.

This particular colony is growing on the dead skeleton of another athecate hydroid colony. The flesh-coloured area lower-left is a sponge. Both these pictures were taken underneath Ngapipi Bridge, along Auckland's Tamaki Drive, 20/9/16.


More info:

See Day 11 and Day 27.

28 — Jellies, Cyanea annaskala

Jelly under Ngapipi Bridge, 20/9/16.

Jelly under Ngapipi Bridge, 20/9/16.

Jelly under Ngapipi Bridge, 20/9/16.

Here's the thing, they're not fish, so we marine biologists don't call them jellyfish anymore, we call them jellies. One of the signs that spring is near is the presence of baby jellies in coastal waters. These ones were being swept into Hobson Bay via Ngapipi Bridge. They're actually quite small, being about 50 mm in bell-diameter.

Here's the thing, they're not fish, so we marine biologists don't call them jellyfish anymore, we call them jellies.

I'll happily admit that I'm not expert enough to tell which species these are, but I'm going to try anyway. I think these are juvenile Cyanea annaskala, Lendenfeld 1882. This species of jelly is cosmopolitan (found everywhere), and is also known as the Lion's Mane. Incidentally, Sir Arthur Conan Doyle wrote a Sherlock Holmes story called The Adventure of the Lion's Mane










More info:

A video clip
http://collections.museumvictoria.com.au/species/8682

http://portphillipmarinelife.net.au/Species/_Species/7761

27 — Not the hydroids you are looking for, thecate hydroids

Thecate hydroid colony, under Ngapipi Bridge,
Tamaki Drive 19/9/16.

Thecate hydroid colony, under Ngapipi Bridge,
Tamaki Drive 19/9/16.

Thecate hydroid colony, under Ngapipi Bridge,
Tamaki Drive 19/9/16. Looking inside the colony
from above.

These are thecate hydroids. Like the athecate hydroids they like places where there's something to attach to, but also lots of current. These colonies come from underneath Ngapipi Bridge, along Auckland's Tamaki Drive, where there is a large tidal flow.



































More info:

A NIWA monograph on New Zealand thecate hydroids

http://www.teara.govt.nz/en/biographies/5r4/ralph-patricia-marjorie

26 — Margin shells, Serrata fasciata

Serrata fasciata, Mt. Maunganui, 1980's.

These are margin shells (Family: Marginellidae). They are quite commonly found in the north of the north island, at and below low tide (down to ~20m) under rocks on moderately exposed shores. Even though they are common, they don’t often get seen because they’re only about 7mm in size. This particular species was, for many years called Marginella (Haloginella) mustelina, but recently it was found that its identity was unclear.

It turns out that there are two similar species, one endemic to Australia and the other New Zealand. For most of the last century the New Zealand species had been confused with the Australian one and as such they’d been called the same thing. The New Zealand species was called the same name as the Australian one—not sure if it was another piece of Australian cultural appropriation...

Anyway, in 2004 it was recognised (see the paper linked below) that these were in fact two separate species and the New Zealand one was given a new name: Serrata fasciata (Sowerby, 1846). By new name, it’s really an old name that wasn’t being used for anything anymore (it’s actually a wee bit more complicated than that). See the link below if you’d like to know more about the arcane ways in which animals get their their names changed. It's all to do with who did what first...


More info:

Marshall, B. A. (2004). New names for four common Marginellidae (Mollusca: Gastropoda) from northern New Zealand. Molluscan Research, 24, 7–20.

For more pictures: http://www.mollusca.co.nz/speciesdetail.php?speciesid=1221&species=Serrata%20fasciata

25 — Deep-sea turrid, Bathytoma (Riuguhdrillia) parengonius

Bathytoma (Riuguhdrillia) parengonius
Challenger Plateau 2007.

This is a turrid from the deep-sea and came from a research voyage out to the Challenger Plateau in 2007. It’s called Bathytoma (Riuguhdrillia) parengonius (Dell, 1956), which is a bit of a mouthful. Again, not all that much is known about this species, apart from it seems to be endemic to the northern half of offshore New Zealand, and they get up to about 40mm in size.

This turrid was found in what are called upper to mid-slope depths (~300–1300m). By slope I mean the continental slope, which starts at the edge of the continental shelf (around about 180–220m). It’s where the gradual gradient of the continental shelf gives way to the steeper continental slope, which then carries on down to the much deeper abyssal plains.

This is a really good introduction to the deep-sea: Ramirez-Llodra et al. (2011). Man and the last great wilderness: Human impact on the deep-sea. It's also an open access journal article, so it's a free download.


More info:

http://www.mollusca.co.nz/speciesdetail.php?speciesid=1280&species=Bathytoma%20%28Riuguhdrilla%29%20parengonius 

http://collections.si.edu/search/results.htm?q=Riuguhdrillia+parengonia&tag.cstype=all

24 — Micro molluscs, various turrids...

Some small turrids. The largest is about 7 mm.
The Cove, south Piha.

These wee sea shells are turrids (Family: Turridae) and these come from The Cove at south Piha. They are a bit worn, but as far as I can tell there could be two species here. The long narrow ones could be in the genus Liracraea and the more rounded ones could be Neoguraleus. Or they could all be in either of the two genera. These were collected in April 2004. Chances are that these wee shells are endemic to New Zealand.


More Info:

http://collections.tepapa.govt.nz/search?searchTerm=liracraea&scope=all&imagesOnly=true

23 — Micro molluscs, Zemitrella stephanophora

Zemitrella stephanophora, Mt. Maunganui,
17/4/1984.

More micro-molluscs: Zemitrella stephanophora * is a small (~7 mm) dove shell**. It is a handsome little shell with colourful markings. Apart from that, not very much is known about this species.

It's known from the north of New Zealand down to the Bay of Plenty. This particular one was collected dead in a rock pool, at the base of Mt. Maunganui on the 17th of April 1984.

*(Suter, 1908)
**Family: Columbellidae

22 — Giant shore anemone, Oulactis magna

Giant shore anemones, south Piha, 13/9/16.

The side of a giant shore anemone with a parasitic
snail (Epitonium (Hyaloscala) jukesianum),
(lower centre left). The Gap, south Piha, 2015.

Juvenile, south Piha, 2016

Juveniles, south Piha, 2016.

South Piha, 2016.

Adult giant shore anemones, south Piha, 2016.

Rock pool assemblage of giant shore anemones,
south Piha, 2016.

Juvenile, south Piha, 2016.

Juveniles, south Piha, 2016.

Juvenile, south Piha, 2016.

Juvenile, south Piha, 2016.
Unusual colour pattern.

Juveniles, south Piha, 2016.

Lion Rock, Piha, 2016.

A juvenile among little
black mussels, south Piha, 2016.

Juvenile, south Piha, 2016.
Unusual colour pattern.

Stoney Point, Mt. Maunganui, 4/11/17,
showing the anemone's stalk.

Stoney Point, Mt. Maunganui, 4/11/17,
showing the anemone's stalk and spent
acrorhagi (white pustules with holes in them).

The giant shore anemone (Oulactis magna Stuckey, 1909) is a large (up to 12 cm across the disc) and spectacular sea anemone, endemic to, and found throughout New Zealand. It is found in areas of high wave exposure and clean water, from mid to low tide. You tend to see them on exposed coasts were rocks meet sand.

Giant shore anemones are particularly common on the west coast of Auckland, where dozens of large colourful anemones can be found in almost every deep rock pool. They are at their most colourful when they are small, often with an amazing array of colour schemes. Once they grow larger they tend to assume a single colour combination.

Often at Piha sand is scoured away from the rocks, exposing new potential living areas for these anemones and other marine life. Then there seems to be a rapid influx of beautiful juvenile anemones which quickly colonise this new living space. However, this can all be be in vain, for the sand can just as quickly return, burying and killing off these opportunistic invaders.

Not much seems to eat these anemones, although occasionally you do see them with what appear to be bites taken out of them. However, a small snail called a wentletrap (Epitonium (Hyaloscala) jukesianum Powell, 1924), is known to parasitise them. It uses a modified radula (mouth parts) to pierce the anemone and feed on its bodily fluids.

You often see this species of anemone at the bottom of rock pools, which is a great place to be if other animals get detached and fall off. You sometimes see the empty shells of little black mussels in the centre of the anemones, which could be seen as evidence for this.



































































































More info:
Anemone guide: https://shapeandtheidea.wordpress.com/2015/10/13/giant-shore-anemone-oulactis-magna/

Morton, J. E., & Miller, M. M. 1968. The New Zealand Sea Shore. Collins.

21 — Skeleton shrimps, Caprellidea

Small rock pool critters, south Piha, 13/9/16.

Small green algae—the same rock pool.

Something about the benefits of looking closely… I was out at Piha today surfing, but while I was checking the surf from some rocks I took the opportunity to sticking my underwater camera into a rock pool and took a few pictures. Most of them didn’t really come out, as I was dodging the surges between photos and there was a lot of water moving around. I was mostly taking pictures of anemones, but I did take some of just general rock pool in the hope of seeing something interesting. It turns out that I did.

The first thing I noticed were the small structures sticking out of a small mussel shell (centre right). They poke up and have very small tentacle-like protrusions coming from their tips—each with a little blob on the end. These are tiny athecate hydroids (related to corals). They would be about 5 mm high. The golden-coloured structures at the bottom of the picture are also hydroids, but they're too blurry to identify with more certainty.

Then I noticed a blurry thing off to the left (I really wish this was in focus, but I was lucky to see it at all). This is a caprellid amphipod or skeleton shrimp, which is standing upright in the foreground attached to some green filamentous algae. I’ve photographed them before, but as they’re small and camouflaged, you don't see them until you blow the photo up.

Skeleton shrimps eat a variety of things, from algae to protists and diatoms. They have also been seen cleaning algal films of the stalks of hydroids, which would be beneficial for both parties; the hydroid gets it’s water resistance reduced and the skeleton shrimp gets a food supply and a somewhere to live.



More info:

http://nzetc.victoria.ac.nz/tm/scholarly/tei-Bio07Tuat02-t1-body-d4.html

http://www.asnailsodyssey.com/LEARNABOUT/AMPHIPOD/amphCapr.php

20 — White-striped anemone, Anthothoe albocincta

Anthothoe albocincta, south Piha, 11/9/16.

The white-striped anemone — Anthothoe albocincta (Hutton, 1879) is a small anemone (~2.5 cm across). Found throughout New Zealand and southern Australia, on exposed coastlines at or below low tide. It’s an anemone that’s more common sub-tidally and it can be found down to depths of ~20 m. Around the low-tide mark they like to live under overhanging ledges, out of direct sunlight and they are often found with the striped anemone.

Recent work in New Zealand has investigated the use of this anemone to control the settlement of fouling bryzoans on mussel lines. White-striped anemones were very successful in not only eating lots of the bryzoan larvae, but they also out-competed them for space on the lines. These results suggest a novel role in aquaculture for this and possibly other anemone species.

Not much appears to be known regarding what eats white-striped anemones, but red moki and leatherjackets have been recorded as feeding on them. However, these incidences of predation were not common, so they don't appear to be a major prey item for either fish.

More info:

Sea anemone guide:
https://shapeandtheidea.wordpress.com/2015/10/22/white-striped-anemone/

19 — Striped anemone, Diadumene neozelanica

Diadumene neozelanica, south Piha 11/9/16

The striped anemone — Diadumene neozelanica, Carlgren, 1924 is found throughout New Zealand in areas of clean water and high wave action. They are usually found at low and below low tide, so they’re not often seen. They get their common name from the light and dark brown vertical stripes on the anemone’s stalk. They have many tentacles, these are quite long and fine, and can be whitish-beige to orange-brown in colour.

These anemones particular were under a ledge at the base of Camel rock, south Piha.


More info: 

The anemone guide I built in 2015: https://shapeandtheidea.wordpress.com/2015/10/12/diadumene-neozelanica/

18 — Deep-sea turrid, Kuroshioturris angustata

Kuroshioturris angustata (Powell, 1940).
Off northern New Zealand, location unknown.

This small shell is called Kuroshioturris angustata (Powell, 1940) and is in the family Turridae. It's about 15 mm long, and is endemic to New Zealand. This species is found in relatively deep-water from about 40–550 m and as far south as Chatham Rise.

For some reason no one has yet to adequately explain, there seem to be hundreds of species of turrids in the deep-seas of the world. Turrids are thought to feed on polychaete worms, but very few species have actually been studied.

These ones look slightly chalky due to their shells slowly dissolving. This happens because of the water pressure at depth makes the calcium carbonate become more soluble. Many deep-sea snails secrete a covering called a periostracum and this helps to protect the shell from the corrosive effects of deep waters.


More info:

More pictures: http://www.mollusca.co.nz/speciesdetail.php?speciesid=1387&species=Kuroshioturris%20angustata

http://www.sciencedirect.com/science/article/pii/S0967064509001817