102 — Palmer's trumpet, Proxicharonia palmeri

Named after the diver who first found it at the Poor Knights Islands, Palmer's trumpet (Proxicharonia palmeri (Powell, 1967)) is a small (~50–60mm), trumpet shell found off northern New Zealand. They are much sought-after by collectors and are an attractive orange beneath a brownish periostracum.

Very little is known about their ecology, but a few have been found offshore and some at considerable depths (~500m). This species is closely related to the fossil P. neozelanica (Marshall & Murdoch, 1923), and there was speculation that they were identical, although now these two are considered separate species. They appear to live in between depths which are too deep to SCUBA dive and too close to rocky outcrops to turn up in dredges or trawls.

The P. palmeri below are from an offshore site and at the time they were collected, probably represented the largest number seen at one time.

Proxicharonia palmeri

Proxicharonia palmeri, showing the animal.

Many many Proxicharonia palmeri. This was but a sub-sample.

More info:

http://www.mollusca.co.nz/speciesdetail.php?speciesid=866&species=Sassia%20palmeri

101 — Crimson (immortal) jelly, Turritopsis rubra

Turritopsis rubra, mussel farm,
Waiheke Island, Auckland, 27/02/14.

Turritopsis rubra, south Piha, 26/04/17.

Turritopsis is a genus of small hydrozoan jellies (<10mm). There are a few species and there appears to be some debate regarding the number. They have a complex lifecycle, which starts off when eggs are released by the medusa (jelly) phase into the plankton. Assuming they survive, they then hatch and settle as a cyst-like blob and form polyps. The polyps then grow and bud off small medusa, which then swim off and grow, produce eggs, and then die. The end.

Turritopsis rubra, mussel farm,
Waiheke Island, Auckland, 27/02/14.

Turritopsis rubra, mussel farm,
Waiheke Island, Auckland, 27/02/14.

Except in Turritopsis dornii it's not necessarily the end. This species can reverse this process, so when times get tough they can revert back into a polyp and wait for conditions to improve. This lifecycle reversal is called transdifferentiation and essentially cheats death, making the jelly biologically immortal.

This transdifferentiation ability enables the jelly to survive long ocean voyages in the ballast tanks of ships and so there is a perception that these little jellies are silently taking over the world's oceans.

As a consequence of their biological immortality, there has been interest regarding the implementation of transdifferentiation in regenerative medicine. However, so far, it appears that the jellies are really hard to keep alive in aquaria making them difficult to study (which seems ironic).

The species pictured here is T. rubra (Farquhar, 1895), which has a south Pacific distribution. It is currently unknown whether this species can transdifferentiate its cells like its close relatives.

These little jellies have quite a painful sting, especially if their tentacles get trapped between a swimmer's (or surfer's) clothing and their skin. The tentacles are long and very fragile, so can break off easily. There was quite a bloom of these little jellies during the summer of 2016–17 on the North Island west coast. Many people thought they were being bitten by sea lice, when in fact they were probably being stung by these jellies. I think "being bitten by sea lice" is a myth.


More info:

Regenerative medicine: http://singularityhub.com/2011/04/25/immortal-jellyfish-provides-clues-for-regenerative-medicine/

100 — Giant squid, Architeuthis dux

A large female giant squid at AUT, 2004.

Three giant squid, defrosting at AUT,
June 2014. Squidcicles...

The least damaged of the three, being made ready
for a live dissection webcast, June 2014.

Giant squid sucker rings from a large female.
These are this colour due to being kept in
alcohol since 2008.

A giant squid sucker ring from a large female.

A giant squid sucker attached to a tentacle.

Another giant squid at AUT, 2008.

The giant squid or legendary Kraken, Architeuthis dux, Steenstrup, 1857, is a very large and iconic squid. It is monophyletic, which means it's the only member of its family, Architeuthidae. In the past there were thought to be many different species, but this was more a reflection of the range of the giant squid and the geographic isolation of the scientists studying them. Giant squid are found worldwide at depths between ~250–1000m. There's quite a lot of information out there regarding giant squid, but some of it isn't very accurate.

Arguably, the biggest piece of misinformation regarding giant squid is their size; they don't get as large as has been reported, but, you can make them quite long if you really stretch the tentacles. The body gets to about 2–3m, while most of their length is made up the feeding tentacles, which can be several metres long. So they can get to around 10–13m in total length depending on which sex they are; females are larger. Also, they can't sink ships.

Ecologically giant squid are thought to be ambush predators, hanging inert in the water column waiting to snatch prey with their two long feeding tentacles. in turn they are preyed on by sperm whales. Stranded sperm whales (Physeter macrocephalus) are often seen with head scars from the suckers of giant squid they have attacked (and probably eaten). It's unlikely that a giant squid would have much of a chance against a sperm whale.

In the past giant squid were really only seen when they washed up (usually quite damaged). However, these days they turn up as bycatch in deep-sea trawl fisheries. In New Zealand waters they are occasionally taken as bycatch in the hoki fisheries off the west coast of the South Island.

One last point: you can't eat them, as they are filled with ammonia. The ammonia ions are lighter than water, so it is thought that is aids in buoyancy.

Here's a video of giant squid expert Dr. Steve O'Shea examining a giant squid at AUT in 2008 (he's a bit sweary, so nsfw).



















More info:

http://squid.tepapa.govt.nz/resources

https://www.tonmo.com/pages/architeuthis-age/

99 — Small ostrich foot shell, Pelicaria vermis

Pelicaria vermis, off Pakiri Beach ~20–30m.
Cast up on Kohimarama Beach as part of the
2004 beach replenishment programme.

Pelicaria vermis (flemingi form). A larger and
wider form from Mt. Maunganui's Ocean Beach.

Pelicaria vermis (tricarinata form), Castlecliff
Beach, Jan 1985. Pleistocene fossil form.

All three together. The flemingi form
 is on the far left. The largest is about 50mm.

Pelicaria vermis (Martyn, 1784) is the smaller of the two ostrich foot shells (Family: Struthiolariidae) found in New Zealand waters; it is also the less common of the two. Many more species exist in New Zealand's fossil record, some of which date back at least 40 million years.

Pelicaria vermis is restricted to the North Island and the top of South Island—although this distribution doesn't appear to be temperature related, as they are also found in considerable depths (down to ~300m, where the water is quite cold).

Unlike Struthiolaria papulosa, P. vermis is a direct-developer—meaning that there is no planktonic larval stage, so when the egg hatches out crawls a miniature version of the adult. This direct-development has interesting evolutionary implications, as it is possible for populations to become genetically isolated since there is no planktonic dispersal phase. This is one way new species can arise (a process called speciation).

About 40 years ago it was thought that there were several regional sub-species from various parts of New Zealand. However, it is now considered that there is one, rather variable species, since it turns out that these various forms actually intergrade. Maybe in a few thousand years they might become different species, maybe not...

Ecologically, they feed in a similar way to their larger cousin: buried in the sediment, consuming plankton via currents driven by cilia. However, they appear to differ in that they can tolerate muddier sediments and deeper water.









More info:

https://www.gns.cri.nz/static/Mollusca/taxa/BM514.html

98 — Carinated nudibranch, Atagema carinata

Atagema carinata, Mt. Maunganui, 2014.

Atagema carinata, Mt. Maunganui, 2014.

Atagema carinata, Mt. Maunganui, 2014.

Notes on Atagema carinata from Mt. Maunganui
(Williams 1967 p19).

Atagema carinata (Quoy & Gaimard, 1832) is a medium-sized nudibranch (~60mm) endemic to New Zealand (apparently found throughout, although records are very patchy) and one not often seen. This may be because they aren't very common, but it could also be that there are few people looking who would know what it was if they saw one.

They have a "skin two sizes too big" look to them, or look a bit like a nudibranch wearing an overcoat. Larger ones also possess a dorsal keel. This species is another which appears to be an ecological void—pretty much nothing is known about them.

This one was seen under a small rock ledge, at the low tide mark on the northwestern side of the base of Mt. Maunganui, 24/12/14. There was another one in the same large rock pool; it was on some red algae.













More info:

Sea Slug Forum: http://www.seaslugforum.net/find/atagcari

Williams EG, 1967. Molluscs from the Bay of Plenty. Whitcomb & Tombs Ltd.

97 — Ostrich foot shell, Struthiolaria papulosa

Struthiolaria papulosa, Pilot Bay,
Mt. Maunganui, 2015.

The ostrich foot shell Struthiolaria papulosa (Martyn, 1784) is almost ubiquitous on sandy beaches around New Zealand. Examples from the north reach about 70mm and have sharp knobs on the spire whorls, while southern forms (gigas) are larger (~90mm) and are smooth, without sharp knobs. They are considered to be one variable species, as there is a general gradation between the two forms moving north to south.

Struthiolaria papulosa, position buried in sand
while feeding. From Morton (1951).

Struthiolaria papulosa is a deposit feeder and sits just below the surface sediments, using complex ciliary currents to essentially inhale its food. This food consists of coarsely graded detritus and micro-organisms, such as benthic diatoms and Foraminifera. Since they live close to the surface, they are easily disturbed by wave-action and after storms can be washed ashore in their thousands.

The Struthiolariidae have a rich fossil history in New Zealand, although today there are only two extant species: Struthiolaria papulosa and the much smaller Pelicaria vermis (Martyn, 1784). Pelicaria vermis lives in deeper water than S. papulosa and is less common.

Struthiolaria papulosa (gigas form).
Stewart Island Jan 1996.

Struthiolaria papulosa (gigas form).
Detail of spire sculpture,
Stewart Island Jan 1996.

More info:

Morton JE, 1951. The ecology and digestive system of the Struthiolariidae (Gastropoda). Quarterly Journal Microscopical Science, 92, 1–25.

More pictures: http://mollusca.co.nz/speciesdetail.php?speciesid=768&species=Struthiolaria%20papulosa

96 — Knobbed whelk, Austrofusus glans

Austrofusus glans, Waikanae Beeach, 1982.

Austrofusus ?glans. Main Beach, Mt. Maunganui,
2016.

A gradation of Austrofusus cf. chathamensis,
Ocean Beach, Mt. Maunganui.

Austrofusus cf. chathamensis,
Ocean Beach, Mt. Maunganui.

The knobbed whelk, Austrofusus glans (Röding, 1798) is a smallish (~50mm) whelk, endemic to New Zealand and found from the intertidal down to considerable depths (~200–300m). It is very common and the only whelk to be commercially harvested.

They were introduced into New Zealand's quota management system (QMS) in 2006, but as they are a low-value species, they are mostly taken as bycatch in bottom-trawls for other species. A. glans are reported to be scavengers, although data are scant regarding ecological interactions with other species.

The genus Austrofusus has a rich fossil history in New Zealand dating back about 11 million years. But now there are only two extant species: A. glans from mainland New Zealand and A. chathamensis Finlay, 1928, from the Chatham Islands.

Personally, I'm not convinced that A. chathamensis exists, as I have examples from Mt. Maunganui which intergrade between the two forms. I suspect that this is yet another issue to be resolved using molecular techniques. Who knows, I could be completely wrong.











More info:

More pictures: http://www.mollusca.co.nz/speciesdetail.php?speciesid=1068&species=Austrofusus%20glans#prettyPhoto

Fossil history: https://www.gns.cri.nz/static/Mollusca/taxa/BM539.html

95 — Trumpet shell, Charonia lampas

Charonia lampas,
Pilot Bay Wharf, 9/02/15.

The trumpet shell, Charonia lampas (Linnaeus, 1758) is an iconic sea shell and immediately recognisable from their large size (~20–25cm) and colourful markings. For a long time it was thought that there were several species scattered around the world. However, current thinking is that there's one variable species found in temperate waters from the north Atlantic and Mediterranean Sea, to the south Pacific. They can be found in a variety of habitats from shallow waters down to continental shelf depths.

Charonia lampas feed on echinoderms, particularly sea stars, but will also consume sea-cucumbers and urchins. While they are occasionally seen sub-tidally, your best chance to see one of these large gastropods is during the summer months, when they come into the intertidal zone to breed and lay eggs.

Their numbers have been depleted through collecting and from the affects of toxic antifouling paints. However, it does seem like they are making a comeback, which is great as they appear to perform an important ecological role controlling the sea star populations. It would be nice if these large charismatic gastropods continued to recover.

Charonia lampas, Pilot Bay, 9/02/15.
This is how you find them. My bag for scale.

Charonia lampas,
Pilot Bay, 9/02/15.

Charonia lampas,
Pilot Bay Wharf, 9/02/15.

More info:

http://www.tandfonline.com/doi/full/10.1080/00222933.2012.724721?scroll=top&needAccess=true

More pictures: http://mollusca.co.nz/speciesdetail.php?speciesid=856&species=Charonia%20lampas