Monday 31 October 2016

68 — Tube worm, Spirobranchus cariniferus

Piha Beach, 6/01/15.
Piha Beach, 31/10/16.
It's fair to say that marine worms aren't exactly charismatic megafauna. However, they can be quite beautiful if seen in a favourable context. The common intertidal tube worm Spirobranchus cariniferus (Gray, 1843) is found throughout New Zealand. They are abundant on moderate to exposed rocky shores. These tube worms are filter feeders, taking material out of the passing water.

The feeding crown of the worm is a brilliant blue, but it is not often noticed, as the worm will withdraw it into its tube at the slightest nearby vibration. Consequently they need to be approached with a degree of stealth, as it takes a few minutes for them to re-emerge once they're retracted. What is usually seen are the calcareous tubes, which have a sharp dorsal (top) spine covering the opening of the tube; it's sharp and easy to cut yourself with.

These tube worms come from south Piha Beach, west of Auckland.





Sunday 30 October 2016

67 — Robust lined whelk, Buccinulum robustum

Buccinulum robustum
Buccinulum robustum Powell, 1929, is another of those small (~15mm) sea shells for which there is very little in the way of ecological data. They are endemic to the north eastern part of New Zealand's North Island, where they are found around the low tide mark down to ~55m.

Buccinulum robustum
Buccinulum robustum
One of the challenges with these buccinulid whelks is that many species are not only superficially similar, but also quite variable morphologically. Consequently, it can be quite difficult to tell where one species stops and another begins. These specimens were collected from near Little Hat Island, Whangarei, 30/9/07.


















More info: 

More pictures of B. robustum: http://www.mollusca.co.nz/speciesdetail.php?speciesid=1079&species=%20robustum#prettyPhoto

Saturday 29 October 2016

66 — Red warratah anemone - Actinia tenebrosa

Actinia tenebrosa, Tamaki Drive,
Auckland, 12/15.
Actinia tenebrosa, Tamaki Drive,
Auckland, 12/15. The small snail just above the
anemone is Risellopsis varia (Hutton, 1873).
Actinia tenebrosa, Tamaki Drive,
Auckland, 12/15.
The red warratah anemone (Actinia tenebrosa Farquhar, 1898) is the anemone most people see around New Zealand as a small dark reddish blob at mid-tidal level. It's found throughout New Zealand and the southern parts of Australia. This is a very hardy species and has been known to tolerate temperatures of up to 49°C in western Australia.

It is thought that its distribution is controlled by predators on the lower shore: it could live lower, but there are animals there which can eat it if it tries to, so it survives higher up where they can't reach it.

In New Zealand waters red warratah anemones can be eaten by the sea-slug Pleurobranchaea maculata if they get too low on the shore and juveniles can be mowed down and squashed by chitons. This is a good example of how an intertidal animal's distribution can be controlled by biological and not physical factors (e.g., desiccation, wave exposure).











65 — Deep-sea moon snail, Globisinum sp.

Globisinum sp. ~12mm.
Globisinum sp. ~12mm.
New species are discovered in the deep-sea almost daily. But there more species being discovered than there are people to officially describe them and give them names. Therefore, there is quite a lag between the time a species gets discovered and when it gets named. As a consequence there are many species which don't yet have official scientific names (called undescribed species), and this is one of those.

This is a moon snail, belonging to the family Naticidae. Naticids tend to be predators and bore holes in the shells of their prey (often bivalves). The holes have bevelled sides, so if you find a shell with such a hole, it was probably predated by a moon snail.

This moon snail belongs in the genus Globisinum. There is a species of this genus (called a cogener) already known from New Zealand waters: Globisinum drewi (Murdoch, 1899), but this one is a new undescribed species. It has a higher spire (and other less obvious differences) than G. drewi and also lives in much deeper water.

The brown colour of the shell possibly either an outer covering (periostracum), or the result of coming into contact with the digestive juices inside the guts of a deep-sea fish.

Rough-head rattail
Fishes can make very good collectors of marine samples, particularly when it comes to hard-shelled invertebrates like gastropods and bivalves. This undescribed Globisinum species came from the intestines of a rough-head rattail (Coelorinchus trachycarus McMillan & Shcherbachev, 1999), which was caught in 1062m of water on the north eastern Chatham Rise.

Fishes can go into areas which trawls or grab samples can't and therefore their gut contents can often reveal more than mechanical sampling methods.

Rattails (Pisces: Macrouridae) are a common group of deep-sea fishes and there are many species found in New Zealand waters. They possess a gas-filled swim bladder (to regulate buoyancy) and when they are brought to the surface, this bladder expands rapidly, killing the fish and voiding all of it's stomach contents. As a consequence the only way to directly ascertain the diet (and their position in deep-sea food webs) is to look in their intestines.

More info:

Jones, M. R. L., 2008. Dietary analysis of Coryphaenoides serrulatus, C. subserrulatus and several other species of macrourid fish (Pisces: Macrouridae) from northeastern Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research, 42, 73–84.



Friday 28 October 2016

64 — Stalked barnacle, Smilium spinosa

A stalked barnacle, in a cave at north
Piha, 26/12/15.
A stalked barnacle, in a cave at north
Piha, 26/12/15.
A stalked barnacle, in a cave at north
Piha, 26/12/15.
Most of the barnacles people are familiar with are the acorn barnacles seen on rocks between the tides. However, they are not the only kind of barnacle. There are also stalked barnacles. These are barnacles which have a flexible stalk attaching them to the rocks, rather than a calcareous base.

Stalked barnacles are not as common as acorn barnacles, but can be found if you are patient and know where to look. Smilium spinosa* is a stalked barnacle often seen in caves and dark crevices around the New Zealand coastline. There a few species of stalked barnacle found around New Zealand and this is the largest and most common.

Why they live in caves is not clear. It could be to avoid predators or to protect them from desiccation.

They are about 30–40mm in size and commonly seen in the caves at the northern end of Piha beach, which is where the these pictures were taken. They co-occur with the anemone Actinia tenebrosa (which are the red blobs).

*(Quoy & Gaimard, 1834)








More info: 

http://rsnz.natlib.govt.nz/volume/rsnz_83/rsnz_83_02_005360.pdf

Thursday 27 October 2016

63 — Brooding anemone, Handactis nutrix

Handactis nutrix, Mt. Maunganui, 2015.
Handactis nutrix, Mt. Maunganui, 2015.
Handactis nutrix, Mt. Maunganui, 2015.
The brooding anemone Handactis nutrix (Stuckey, 1909) is so named due its ability to shelter juvenile anemones in a fold around its base. It is found throughout New Zealand and southern Australia, at and around low tide on brown seaweeds (particularly Cystophora, Xiphophora, and Carpophyllum). All of the anemones pictured below are attached to Carpophyllum maschalocarpum (Turner) Greville 1830.

When they are disturbed brooding anemones exude long white threads (called acontia), which are filled with stinging cells and used to deter would-be attackers.

Fishes seem to be the main predators of brooding anemones, including snapper, yellow-bellied flounder, tarakihi, and blue cod. However, Morton & Miller (1968) reported that a small sea slug Baeolidia australis (Rudman, 1982) also feeds on this anemone. Apparently, this slug is only found in northern NZ, so it seems that fishes could be the anemone’s main predator throughout the rest of its range.








More info:

More pictures of the brooding anemone

Wednesday 26 October 2016

62 — Deep-sea turrid, Gymnobela gypsata

Gymnobela gypsata Stn 56, NW
Challenger Plateau, ~1000m, 31/5/07.
Gymnobela gypsata Stn 56, NW
Challenger Plateau, ~1000m, 31/5/07.
Gymnobela gypsata Stn 56, NW
Challenger Plateau, ~1000m, 31/5/07.
Gymnobela gypsata * is another of those deep-sea gastropods for which very little is known. It appears to be endemic to deep-waters around New Zealand, and at depths down to at least 1700m. They can get to around 45 mm, so they're a reasonable size.

I've come across them a couple of times: a small one came from the intestines of a ridge-scaled rattail **, which was caught on the NE Chatham Rise from a depth of 1062m. The ones pictured here were collected from the north west Challenger Plateau during the Oceans 20/20 TAN0707 voyage, when a few of them came up in a beam trawl from ~1000m. My thanks again go to NIWA for my place on that trip.


*(Watson, 1881)
**(Macrourus carinatus (Günther, 1878))















More info:

http://www.tandfonline.com/doi/abs/10.1080/03036758.2011.548763

Tuesday 25 October 2016

61 — Mussel's beard, Amphisbetia bispinosa

Mussel's beard Amphisbetia bispinosa and
gammaridean amphipods, Lion Rock, Piha.
Mussel's beard (Amphisbetia bispinosa (Gray, 1843)) is not a beard, or indeed made by mussels. It is actually a colony of thecate hydroids. Theca means cup, so each individual hydroid lives inside a cup-like structure.

Hydroids are related to jellies and sea anemones. Mussel's beard is (not surprisingly) found mostly on mussels—particularly the green-lipped mussel*. However, colonies are also common on wharf piles. They are found throughout New Zealand and southern Australia.

Mussel's beard Amphisbetia bispinosa and
gammaridean amphipods, Lion Rock, Piha.
The pictures here come from Lion Rock, Piha, 24/10/16. The animals amongst the mussel's beard are gammaridean amphipods, which are abundant in the intertidal rock pools there. The amphipods are about 5–7mm in size.
Mussel's beard Amphisbetia bispinosa and
gammaridean amphipods, Lion Rock, Piha.


*Perna canaliculus (Gmelin, 1791).



Sunday 23 October 2016

60 — Micro molluscs, Herpetopoma bellum

Two Herpetopoma bellum, Devonport,
Auckland, 30/09/15.
Herpetopoma bellum, Devonport,
Auckland, 30/09/15.
Herpetopoma bellum * is another micro mollusc (~5 mm), which is relatively common, but easily overlooked. They are found throughout New Zealand and Tasmania and like moderately exposed coastlines, where they live under rocks.

They are easily missed because usually they are covered with a layer of orange sponge (thought to be Microciona coccinea Bergquist, 1961). The shell underneath is granulated (rough with small even rows of beads) and the aperture in nacreous.

The two pictures here were taken during a spring low tide during 2015 at Devonport, Auckland.

(Hutton, 1873)



Saturday 22 October 2016

59 — Sinclair's turrid, Neoguraleus sinclairi

Neoguraleus sinclairi, Tamaki Drive,
Auckland, 9/04/16.
Two N. sinclairi converge. Tamaki Drive,
Auckland, 9/04/16.
Neoguraleus sinclairi, Tamaki Drive,
Auckland, 9/04/16.
Sinclair's turrid, Neoguraleus sinclairi* is a small sea shell (~10 mm), which is often seen washed up on the tide line of sheltered sandy beaches throughout New Zealand (where it is endemic). This is because they particularly like living on sea-grass flats.

There are several similar species in this genus and they can be a real challenge to tell apart. Neoguraleus sinclairi and N. murdochi (Finlay, 1924) are probably the most easily confused, as their shell morphology is very similar and differences in anatomy need to be studied to tell them apart. However, N. murdochi is found in deeper water than N. sinclairi and is less common, so the latter species is the one that gets seen most often.

Despite its reported abundance, it's another species for which there is scant ecological knowledge. We have a pretty good idea where it lives, but we don't know what it lives on, or what (if anything) feeds on it. A lot of turrids feed on polychaete worms, but whether these do is purely speculation. There's also very little data regarding how many there actually are, so they are what we call data deficient.

The second picture below is really interesting as it shows an interaction between two N. sinclairi. If you follow the tracks back from the centre right you can see them cross and then diverge. This suggests that there one snail crossed the track of another, then turned and followed it. Chances are they were converging to mate, but that's speculation...

* (Gillies, 1882)













































58 — Olive anemone, Isactinia olivacea

Some green Isactinia olivacea, Lion Rock, Piha,
22/12/15.
The olive anemone (Isactinia olivacea (Hutton, 1878) is a common sight on rocky beaches around New Zealand and southern Australia. They're a smallish green–brown-coloured anemone, which can also be greener or browner depending on the population.

Olive anemones are interesting, because they (like tropical corals) contain symbiotic photosynthetic algae (zooxanthellae). Healthy zooxanthellae produce starches, which the corals can't consume, so corals keep their zooxanthellae in a slightly starved state. Then the algae's metabolism produces sugars, which the coral can use as food. This is the basis for the symbiosis between the two organisms: the zooxanthellae get a place to live, but not quite all the food they can eat, while the coral gets a food source in return for some house guests.

Some brown Isactinia olivacea, South Piha,
15/04/16.
Having the zooxanthellae extends the range of viable habitats for the anemone. It may enable to anemone to live higher on the shore out of the reach of crawling predators.

Olive anemones also contain carotenoid pigments and it has been speculated that these act as a kind of sunscreen, protecting the anemone from sunburn; they are often seen in direct sunlight, with their tentacles fully extended.

Isactinia olivacea, Pilot Bay,
Mt. Maunganui, 27/7/18.
Like corals, anemones can bleach when placed under stress and may eventually die without their zooxanthellae. However, it's not an area with a great deal of research.











More info:

More on olive anemones

Wednesday 19 October 2016

57 — Polyclad flatworm, Thysanozoon cruciatum

Thysanozoon cruciatum, under Ngapipi Bridge,
Tamaki Drive, Auckland, 19/10/16.
Thysanozoon cruciatum, Takapuna Reef,
Auckland, 2015. The head is on the left.
Thysanozoon cruciatum, under Ngapipi Bridge,
Tamaki Drive, Auckland, 19/10/16.
Thysanozoon cruciatum, under Ngapipi Bridge,
Tamaki Drive, Auckland, 19/10/16.
Thysanozoon cruciatum, under Ngapipi Bridge,
Tamaki Drive, Auckland, 19/10/16.
Thysanozoon crucatum, Takapuna Reef,
Auckland, 2015.
Polyclad flatworms are superficially similar to sea slugs, but belong in the order Polycladida; the name referring to the many branches of their gut. There are several species found in the Auckland region and this one is Thysanozoon cruciatum Schmarda, 1859. They get their name from the cross-like lighter area on their dorsal surface. I think that Thysanozoon might be my favourite genus name; it sounds like the name of an anime villain.

Anyway, it doesn't look these animals have been well studied in New Zealand waters and it's difficult to get information regarding their distributions. However, T. cruciatum is thought to be endemic to New Zealand (de Cook, 2010).

Polyclad flatworms are thought to be either predators or scavengers. They can be really bright colours or they can be camouflaged.

They are quite beautiful when they swim; even though these ones mostly crawl around like a small shag-pile rug. This species reminds me of a bathroom mat I used to own.






































More info:

An identification key:
http://pick4.pick.uga.edu/mp/20q?guide=Rhabditophora&flags=not_no:

https://www.rzuser.uni-heidelberg.de/~bu6/flatintr.htm

de Cook, S. (2010). New Zealand coastal marine invertebrates. Canterbury University Press, Christchurch.

Tuesday 18 October 2016

56 — Southern olive, Amalda australis

Amalda (B.) australis, Mount Beach,
Mt. Maunganui, 17/11/17.
Tamaki Drive, Auckland, 10/15.
This is the small lump in the sand made
by an emerging southern olive, July 2018.
Mount Beach, Mt. Maunganui, 08/15.
Tamaki Drive, Auckland, 10/15.
The southern olive (Amalda (Baryspira) australis * is an attractive medium-sized shell. They get to about 40mm in length and are endemic to New Zealand. Southern olives are found in the low intertidal (and sub-tidally down to a few metres) on sheltered sandy beaches. Their distribution extends from throughout North Island down to the top of South Island.

Just after the tide turns and starts to come in southern olives can often be seen as a small lump in sand. They are surprisingly fast moving species (see video clip) and if disturbed can re-bury themselves in about a minute.

Most olive shells are predators, although I've not been able to find any specific information regarding southern olives.


*(G.B. Sowerby I, 1830).













































More info:

Haward, B. W., & Morley, M. S. 2005. Intertidal life of the Tamaki Estuary and its entrance, Auckland. Prepared for Auckland Regional Council. Auckland Regional Council Technical Publication Number 373. 72p

More pictures: http://www.mollusca.co.nz/speciesdetail.php?speciesid=1211&species=Amalda%20(Baryspira)%20australis

A paper reveiwing the genus Amalda in New Zealand:
http://olivirv.myspecies.info/sites/olivirv.myspecies.info/files/Review%20of%20the%20genus%20Amalda%20from%20-%20Hart%2C%20M.%20%28Mike%29.pdf

55 — Bubble shell, Bulla quoyii

Bulla quoyii, Mount Beach,
Mount Maunganui, 2015.
Bulla quoyii, Okahu Bay, Auckland, 28/11/15
Bulla quoyii (centre right), within it's
 mucous 'nest'. The light-coloured material
to the left is also part of the nest.
Okahu Bay, Auckland, 28/11/15.
There are a few species of bubble shell (Bullidae) in New Zealand. Bulla quoyii Gray, 1843 is the largest (~50mm) and one of the most common. It's found throughout North Island and the top of the South, plus southern Australia. They like sheltered waters and can often be found amongst sea grass meadows (Zostera sp.).

They are thought to be herbivorous, feeding on Enteromorpha sp. and other green algae (Malaquias et al., 2009). Rudman (1971) reported that in deeper sub-tidal waters they can also feed on red algae, e.g., Pterocladia lucida.

As with other Bulla species, they can sometimes be found within a mucous nest, which the snail builds. However, I've not yet been able to discern the function of this nest—perhaps it's an aid to camouflage at low tide or while the animal feeds...
















More info:

Malaquias, M. A. E., Berecibar, E., Reid, D.G., 2009. Reassessment of the trophic position of Bullidae (Gastropoda: Cephalaspidea) and the importance of diet in the evolution of cephalaspidean gastropods. Journal of Zoology, 27, 88–97.

Rudman, W. B., 1971. Structure and functioning of the gut in the Bullomorpha (Opisthobranchia). Part 1. Herbivores. Journal of Natural History, 5, 647–675.

Seaslug forum: http://www.seaslugforum.net/find/bullquoy

Sunday 16 October 2016

54 — Armless stars, Brisinga sp.

Brisingid starfish, Challenger Plateau,
TAN0707, 29/5/07.
These are a kind of deep-sea sea star, which belong to the order: Brisingida. They get their common name from their fragility: they tend to come up in trawls with all their arms missing.

Brisigids are found throughout the world and there are quite a few species. They are unusual, as they have a body plan adapted for suspension-feeding (catching small particles of food out of the passing water). In life they look a bit like the skeleton of an umbrella without the handle. They can be really common on the tops of undersea ridges or on seamounts; any habitat where there is plenty of water flow to bring them food.

Brisingid starfish, Challenger Plateau,
TAN0707, 29/5/07.
The pictures are of a New Zealand species from about 600m depth on Challenger Plateau west of New Zealand; it might be in the genus Brisinga.









More info:

http://echinoblog.blogspot.co.nz/

https://docs.niwa.co.nz/library/public/NIWAbm120.pdf

https://www.niwa.co.nz/coasts-and-oceans/tools-and-resources/Echinoderm%20ID%20Guide


Friday 14 October 2016

52 — Amalda (Gracilispira) benthicola

Amalda (G.) benthicola, ex-pisces,
Chatham Rise, 07/2004.
This wee sea shell (~10mm) is very little-known. Amalda (Gracilispira) benthicola (Dell, 1956) was, for a long time considered to be a deep-water form of A. (G.) novaezealandiae. However, recently it was discovered that it was a distinct species. What's interesting about this one is how it was obtained...

This example came from the stomach of a deep-sea fish called a serrulate rattail (Coryphaenoides serrulatus Günther, 1878). The fish was caught in 901m of water on northeastern Chatham Rise, not far from the Andes complex of seamounts. Serrulate rattails are deep-sea scavengers and will eat pretty much anything which fits in their mouths. They are found in deep-water (~500–1300m) around New Zealand, south eastern Australia and South Africa. They are commonly taken as bycatch in deep-water fisheries for orange roughy, but since they have no commercial or curio value they are dumped once caught.

Amalda (G.) benthicola, ex-pisces,
Chatham Rise, 07/2004.
Fish stomachs can be really useful vectors for the collection of marine samples, as fish can often go into areas where nets can't and can eat small animals, which would not normally be retained in nets or dredges. A New Zealander called Gordon Williams pioneered this method of collection back in the 1950's and there are molluscan species named williamsi in honour of his contribution. He wrote a book, published in 1964 (which is now very hard to get) detailing his methods and discoveries in the Mt. Maunganui–Bay of Plenty region.






More info:
  http://olivirv.myspecies.info/sites/olivirv.myspecies.info/files/Review%20of%20the%20genus%20Amalda%20from%20-%20Hart%2C%20M.%20%28Mike%29.pdf

51 — Dell's spider crab, Platymaia maoria

Platymaia maoria, Challenger Plateau 2007.
Dell's spider crab (Platymaia maoria Dell, 1963), is a smallish deep-sea crab (to ~69mm across the carapace), found in water ~270–950m deep, which is essentially the upper to mid-continental slope. They are found around the northern part of New Zealand's North Island and across to eastern Australia. This kind of distribution is common to many deep-sea species, some of which can have nearly global distributions.

Platymaia maoria, Challenger Plateau 2007.
Dell's spider crabs tend to turn up as bycatch in deep-water fisheries for orange roughy (Hoplostethus atlanticus Collett, 1889). They're quite fragile little crabs, so I can't imagine that too many come up in one piece. This particular Dell's spider crab came from Challenger Plateau, west of New Zealand in about 500m of water. It was taken in a research trawl, as part of the Challenger Plateau leg of the Oceans 20/20 research voyages of 2007.

Not much appears to be known regarding the ecology of this crab, but it has been speculated (mostly by me) that they might be scavengers.



More info:

NIWA common deep-sea invertebrate guide:
http://deepwatergroup.org/wp-content/uploads/2013/08/Tracey-et-al-2007b-Deepsea-Invertebrate-Guide-f.pdf

Wednesday 12 October 2016

50 — Deep-sea volute, Alcithoe lutea

Alcithoe lutea, Challenger Plateau, TAN0707.
Alcithoe lutea, Challenger Plateau, TAN0707.
Alcithoe lutea, Challenger Plateau, TAN0707.
Alcithoe lutea, on the seabed, Challenger
Plateau, TAN0707.
Alcithoe lutea (Watson, 1882) is quite a rare New Zealand volute (Family: Volutidae), and is only found in deep-water off the west coast of North Island.

These specimens came from NIWA, as part of the Oceans 20/20 Programme (voyage TAN0707).

In the last photo a live A. lutea can be seen moving on the seabed at a depth of about 550m. It's a little hard to see, since I sneakily took a shot of the TV screen from the deep towed camera while no one was looking—I wasn't supposed to, but I thought it was important to document it (asking for forgiveness rather than permission...). The volute is oriented with the spire pointing towards the top left and you can clearly see the long siphon pointing straight down.

Volutes are predators and have a long siphon, which they use to hunt for food. Apart from what you see here, very little is known regarding the distribution, numbers, or ecology of this species.

I'm indebted to NIWA for allowing me on this voyage and letting me have some of the dead shells they didn't need.
















More info: 

http://www.mollusca.co.nz/speciesdetail.php?speciesid=1204&species=Alcithoe%20lutea