Holy Mola; that’s a whole lot of eggs for Easter!

mola easterThe Easter holidays are nearly upon us again, shops stacked floor to ceiling with an incredible array of colourful chocolate eggs… which got me thinking, why so many eggs?

The ocean sunfish (which all my thoughts eventually turn to) is well known for being the most fecund vertebrate on earth with a single female estimated to contain 300 million eggs!

But why so many? Eggs are energetically expensive to produce and tiny offspring are vulnerable to predators, so from the outskirts this seems like a strange and risky reproductive strategy.

The number and size of offspring an animal produces is often classed into two categories:

1) K Stratagists     2) r Stratagists

The animals grouped as K stratagists chose quality over quantity. They have very few young, but these tend to be larger in size, more developed at birth and enjoy a higher degree of parental care so that although fewer offspring are born, they are more likely to survive to adulthood.

At the other end of the scale are the ‘r stratagists’; animals in this category play the numbers game! They can produce millions of tiny offspring, often with no parental care at all so although the chances of survival are low for the individual, the sheer number of young produced means that one or two surive against all odds.


Of course we cannot really divide the entire animal kingdom into two arbitary classes, but this provides a useful scale to consider different stratagies for species. The ocean sunfish of course, subscribes to the r strategy with millions of eggs released into the water. We often think of this fish as an oceanic giant with few predators, but of course sunfish start as eggs drifting in the plankton only 1mm in size which puts them right at the bottom of the food chain! The eggs will float around, and if they remain in the right conditions, hatch into tiny fish fry. These fry will need to avoid predators and find enough food to survive, their best defense is to grow larger with increased muscle mass to outswim predators and become too big for predators to pick on. Of course this will only be achievable for tiny proportion of each cohort, but strange as it may seem, this is a successful stratagy that has maintained the population of ocean sunfish for millions of years.

So on Easter weekend, when you are stuffed to bursting with eggs of all shapes and sizes (as I intend to be!), spare a thought for the poor sunfish, for them this is simply business as usual.


So long and thanks for all the fish!


It’s that time of year again, spring is in the air (mostly!) and thoughts turn to summer holidays relaxing on the beach, swimming in the sea, snorkelling over colourful corals and silvery fishes. But what is the future for these seemingly idyllic ecosystems? Current research suggests that coral reef ecosystems globally are under mounting pressure, from warming seas, acidification, over fishing, tourist damage etc., however until this week I was unaware of the potentially wide ranging impacts of the tropical fish trade. As someone who has kept fish as pets and occasionally visits aquariums, I wanted to know more about how fish are sourced for aquaria displays.

finding nemo.jpg

A recent article from National Geographic states that up to 98% of marine ornamental fish cannot be bred in captivity on a commercial scale; therefore they must be collected from the wild, namely from Southeast Asia. According to a report from NOAA in 2008, up to 90% of the 11 million marine aquarium fish imported to the USA are caught illegally using cyanide. Although fishing using cyanide has been banned across the Philippines, Sri Lanka and Indonesia, there is little enforcement and with huge sums at stake, more and more fishermen are turning from fishing for food to supplying the aquarium trade (worth up to $200 million p.a. according to the WWF).


When cyanide tablets are ground down, they can be mixed with water and using squeezy bottles, used to flush out stunned fish from hiding places in the reef. Cyanide impairs movement and breathing in fish and with such an imprecise method of delivery, many simply die. It has been estimated that for each fish collected, a square yard of coral is killed or bleached (which of course has further knock on impacts across the reef ecosystem). It appears that both the fishermen and middle men involved in this trade are very quick to pass on their catch, as there is a high risk of fish death, even some time after collection and then of course the risk is passed onto the unsuspecting aquarium owners who will need to replace their collection if a fish dies. But what can be done to break this cycle and ensure that fish are ethically supplied from sustainable sources?

Bags of fish.

New laws are currently being drafted globally, with new legislation being debated and huge petitions aiming to make cyanide testing and certification of imported fish mandatory. However, this does not reduce pressures on tropical fishes still being collected from the wild in huge numbers, and many are now calling for only captive bred fish to be sold and traded. It is perhaps ironic that after the release of Disney’s film Finding Nemo (in which a wild fish is taken off the reef for a private aquarium and the tank fish fight for freedom in the open ocean), demand for clownfish and tangs shot up by 40% almost overnight.

Although many clownfish species can be bred in captivity, royal tangs are now being over collected and are endangered in the wild. A new app called Tank Watch (developed by the Humane Society of the United States) aims to help people trace reef-friendly species and public awareness campaigns are aiming to educate people (like me) by highlighting the potential back story of each aquarium fish.


Of course on the flip side, the aquarium trade has benefitted some rare species, such as the red-tailed black shark which is critically endangered and possibly extinct in the wild, but thanks to the the interest generated by aquarists,  dedicated breeding programs have been set up and a steady captive population now can help preserve this species.

It’s a contentious issue, with opinions running strongly on both sides, including the “Hands off my hobby” campaign of the Ornamental Aquatic Association who aim to protect the “pleasure [gained from fish keeping] as well as [the] social, economic and
health benefits” of the fish trade to the UK. On the opposing side, marine campaign groups such as Sea imagesShepherd have launched their “Operation Reef Defence” to end the wild caught marine fish trade.

Public support is now building for a European wide investigation into the exotic pet trade, and perhaps the end goal should be to ensure ethical standards and protection of reef ecosystems are upheld so that at the end of the day, everyone can sit back and enjoy the fish.

If you fancy more fishy facts (or if you have found a sunfish washed up) please contact me using the comments section below or follow me on Twitter or Instagram @SunfishResearch  🙂

Myth buster’s blog part 2: Farewell fake news!

Hello and welcome to Part 2 of the special edition Myth Buster’s Blog!! Following the fishy facts touted by sunfish-loathing Scout Burns that went viral last week, I have been exploring the incredible ecology of the ocean sunfish and answering a lot of fake news claims! So buckle up and get ready for a whistle-stop tour of fascinating (and scientifically verified!) fish facts.

My favourite issue that Scout has with sunfish is that despite being “so huge” they are not even “decent predators” …unless you are a prey item of course! The key biological definition of a predator is ‘an animal that naturally preys on others’ and so sunfish are actually classed as oceanic predators!


With jaws not-so-dangerous to people, the sunfish (or Mola) is a voracious predator of gelatinous prey!

 If we consider a “decent predator” as one which is harmful to humans, then as Scout mentioned, sunfish can be dangerous due to their incredible size and are alleged to have caused a death already by breaching and hitting a person. But as a biologist, this doesn’t seem like the best method for classifying predators…(although it should qualify as entry to the Darwin Awards!)

Back to sunfish prey items, (an area quite a few researchers have been working on over the last 5-10 years,) Scout states “They mostly only eat jellyfish because [it has] a possibility of drifting into their mouths I guess. Everything they do eat has almost zero nutritional value and because it’s so stupidly fucking big, it has to eat a ton of the almost no nutritional value stuff to stay alive. Dumb.” Again, this statement needs a bit of work to reach the underlying truth… Yes sunfish mostly eat jellies, but for smaller sunfish (<1 m), up to 40% of their diet is actually made up of seafloor creatures including crustaceans, molluscs and even some fish species. I even wrote a blog post about this 3 years back…

sunfish food

So many choices….

To find jelly prey in the open ocean, not just jellyfish medusae but also other gelatinous creatures such as siphonophores, ctenophores and pyrosomes (see photos!), is a tough job. Sunfish constantly patrol the world’s oceans searching for prey, travelling long distances both horizontally and vertically to find their food. When they locate prey items, such as a jellyfish, they know to only eat the most energetically nutritious parts, the gonads and oral arms (yum!) before leaving the rest as not worth bothering digesting. It’s an incredible strategy that not many creatures are physically able to exploit and something that we are still trying to understand and explain.

Sunfish prey items clockwise from top left: Ctenophore – (Bolinopsis infundibulum), Siphonophore (Marrus orthocanna) and Pyrosome (unknown species)

Photo credit www.photolib.noaa.gov, en.wikipedia.org/wiki, carnivoraforum.com

Scout then moves on from thinking of sunfish prey, to thinking of sunfish as prey: “They do sometimes get eaten though. But hardly. No animal truly uses them as a food source.” Again, this is a little misguided. Although larger sunfish are less predated on (but have still been found inside large sharks, sealions, orca etc.) the sunfish start out life in the plankton as tiny eggs less than 1 mm across. This puts them on the menu for almost every creature in the sea! As they grow, the number of predators able to cope with such a large item decreases, but they are still removed from the world’s oceans in their hundreds of thousands by… you’ve guessed it: us! There are huge markets for ocean sunfish meat across the Far East (Taiwan and Japan in particular) and they are also captured as unwanted bycatch by fisheries across the world. It is these enormous catch figures that have led to the ocean sunfish being classified as Vulnerable to extinction by the IUCN Red List.

Fisheries capture of ocean sunfish and a dish made of sunfish

(Photo credit; Lukas Kubicek and commons.wikimedia.org)

Scout reckons their survival strategy is dependent on the sunfishes extreme fecundity, “it would be statistically improbable, dare I say impossible that there wouldn’t be at least one… left surviving at the end of the day”. The sunfishes incredible fecundity has been estimated from one study that suggested a single female could contain up to 300 million eggs, (although it is highly unlikely that a sunfish would release all their eggs at once!) This number is brandished a lot in ocean sunfish ecology, but we need to remember this figure was estimated from one fish; it does not represent the average number of eggs per sunfish and has not been examined further since the original study in 1921…

The statistically probability of larvae survival is harder to predict… in cases of extreme fecundity (known as being an r-strategist) an animal must produce lots and lots of offspring because the overall odds of survival are minuscule. We don’t currently know how many sunfish there are in the seas, but it appears that not many of these offspring survive otherwise evolutionary speaking, it would be an unnecessary waste of resources and not selected for.

r stratagist.png

A simple outline of species reproductive strategies:

  1. “K strategists” which have fewer offspring with higher energy input and high parental care which are more likely to survive (e.g. polar bear)
  2. “r strategists” which have high abundance of offspring, with low energy input and little to no parental care which have a poor chance of survival (e.g. ocean sunfish)

Of course this rant does not, in my opinion constitute as “proof that God has abandoned us.” But unfortunately Scout feels so strongly to “hate the f*** out of this complete failure of evolution… if I ever see one, I will throw rocks at it.” As much I as love to introduce people to the incredible species I work on, considering that we currently believe these fish are Vulnerable to extinction and seem to have an important role in ecosystem functioning, (and animal cruelty is frowned upon), perhaps it’s best that these two never meet.

If however, anyone ever has any questions on ocean sunfish or wants to know more details about their fascinating ecology please head to my twitter page @SunfishResearch or visit my blog sunfishresearch@wordpress.com


Something Sounds Fishy! Myth Buster’s Blog (1 of 2)

break the internet.png

Incredibly it seems the ocean sunfish has gone viral yet again! I know, I was surprised too! Firstly Boston Man broke the internet with his ideas of catching a ‘baby whale’ (*spoiler, it’s a sunfish!) and now an incredible rant about the “biggest joke played on earth”, again with sunfish as the butt (or should that be swimming head) of the joke! I love a good rant (esp. David Mitchell when he goes off on one), but in the dark days of fake news, there are a few little problems with Scout Burns’ epic tale of “wasted space” that I feel we should explore.


Fishy News Stories…. Time for #FridayFacts!!

Scout has made some pretty big claims about sunfish, the scientists who study them and even the process of evolution itself so I feel it’s time someone stood up for the funny-looking fish and for science itself, so in response today we have a special #FridayFacts edition: The Myth Buster’s Blog!

At the beginning of this viral rant, we are told that sunfish are just “big, dumb idiot[s]” of “the biggest joke played on earth” made when “God must have accidentally dropped [one] while washing dishes one day and shrugged his shoulders” because they have “no purpose… every foot… wasted space”. Of course we cannot agree with this, the ocean sunfish is the brand new kid on the block when we come to looking at species evolutionary speaking! Whereas the fishes as a group first emerged around 500 million years ago, the ocean sunfishes represent cutting edge evolutionary design, having evolved only around 50 million years ago!



Dishes?! More like cutting-edge design

The ocean sunfish showcases a fantastic body honed by selective processes over millions of years, perfectly adapted to a life travelling the world’s oceans. As to their purpose on this planet, this is a bigger question to answer… the meaning of life has been hotly debated for centuries from ancient philosophers to Monty Python (of course the real answer is 42!). But roughly speaking, their “purpose” is the same as the rest of all lifeforms on earth… simply to exist and pass on genes: to feed, grow, breathe, reproduce and die.

The meaning of life and the sunfish life cycle (adult produces offspring as eggs, through larval stages, growing from juvenile to mature adult and the whole cycle starts afresh!)

Of course, having an interest in biology, we want to know a few more details than that! Which is why scientists (myself included) are trying to unravel the complex ecology of the sunfish a little further… but when it comes to scientific understanding, Scout suggests “scientists even debate how [sunfish] move. They have little control… some say they must just push water out of their mouths for direction…They could use their back fin, except… it doesn’t f****** grow. It just continually folds in on itself.”

Now as funny as the idea is of a giant sunfish blowing water to presumably jet backwards (!?!), I am sorry to report that this simply isn’t true. We know how they move and in quite a lot of detail. They use their dorsal and anal fins like a pair of wings to soar through the oceans, undertaking long distance journeys of up to 48km a day! Their funny little caudal fin (known as the clavus) grows of course, and has a vital function (otherwise evolutionarily it would have most likely have been lost!), and is used like a ship’s rudder to steer the fish as it swims.


Similar structures; ships rudder and sunfish clavus

Scout correctly mentioned that sunfish don’t have swim bladders; however it is not true that “that every fish has [one] to make sure it doesn’t just sink to bottom of the ocean… [and sunfish] can barely move to begin with”. Lots of fish do not have swim bladders, for example sharks, as there are other evolutionary designs that can provide lift without the issues of containing air internally (such as problems with rapid descent and ascent). Most fish without swim bladders, including sunfish, have large deposits of fatty lipids in their livers that provide buoyancy = no swim bladder, no problem!


Some of the sunfish’s fellow fishes without swim bladders (left to right: manta ray, great white shark, basking shark, white marlin)

Aside from preventing sinking, Scout also mentions that sunfish seem to “get stuck on top of the water… because without the whole swim bladder thing… the ocean pushes over the [fish]”. This idea again presents a great image, but unfortunately is untrue. The sunfish does not need a swim bladder to remain upright (it’s not a life jacket); they are perfectly capable of swimming upright both at the surface and at depth. Sunfish are often noted “basking” at the surface where they lie on their sides which enables them to increase the rapidity of their heat exchange, to communicate with birds for parasite removal and perhaps simply just to rest, before diving back into the depths (up to 844m deep!)

sunfish depth.png

Seeking the sun in deep, dark places! Ocean sunfish photos at depth

So that’s all we have time for in this Myth Buster’s Blog edition but I will be posting part 2 next Friday to question the remaining “fishy” facts in the “sunfish are useless animals” rant and of course to provide some illuminating answers! *Spoiler alert, sunfish are awesome super-predators!

If you just can’t wait another week for more sunfish news, please check out my twitter @SunfishResearch or please feel free to ask a question using the comments below 🙂


Getting crafty for Science! From paddling pools to pleather harnesses, all in a day’s work!

I am often asked where I find equipment for my research, (obviously sunfish harnesses can be tricky to buy off the peg)… and so this blog is all about sourcing strange bits of kit! Please dive in and feel free to laugh a lot at the awkward places I end up, all in the name of science!

A common strategy for many scientists is to make your own/adapt/invent things to fit your fieldwork and although this may seem a bit Blue Peter “here’s a floating, lightweight holding net I made earlier”, it saves a lot of money and time in the long run!

A “how to” make a floating net (including demo ‘fish’ capture in last photo…)

So to start the blog for 2017, here is the official Weird Kit List! The top 3 things I have bought or made in the name of field work (so far…)

   At number 3: The beef jerky maker/high tech stable isotope dryer!


The state-of-the-art isotope lab in action (in my b&b room *phew!)

At number 2: The suspicious hand pump/chlorophyll extraction device!



The hand pump in action on the beach filtering liters of seawater in double quick time!

And at No. 1: The pleather lovers’ dream/sunfish-harness-making material!


Customised sunfish belts for all!

So as you can see, it’s well worth being a bit inventive (and having a sense of humor) when working in the biological sciences!!

Here’s to another year of invention & adventure and wishing you all a wonderful 2017!

As always if you see a dead sunfish which we could take samples from or just fancy a chat about fish/PhD life/getting crafty for science please get in touch! 🙂

Email: nphillips01@qub.ac.uk

Twitter: @SunfishResearch

Instagram: @SunfishResearch

The unbelievable truth: 7 surprising sunfish facts!

After writing this blog post about the unusual behaviours of ocean sunfish, I was searching for illustration inspiration… and here we are!


Over the last two years I have seen hundreds of sunfish and these close encounters have given me plenty of opportunity to note a few things about their unusual behaviour!

 So here are the seven strangest things I have learned about sunfish so far:

 1.      Sunfish are noisy! It may sound strange, but yes fish really can make noises (a useful communication tool in the marine environment as sound travels more easily through water than air). Our sunfish grumble and grunt (a lot!) in a disgruntled fashion, especially when we weigh them, (but then no-one likes having their weight read out loud I suppose?)

sunfish close up

Puff your cheeks out! (pre-grunt)

2.      They can throw mucus a distance of several feet! I’m pretty sure this is an unintended consequence of being very mucus-y fish with powerful flapping fins, so if anyone else is planning on working with them, beware of flying gunk -it gets everywhere: clothes/arms/ears/hair etc. eugh.

3.      Sunfish can projectile poop. Yes you heard me, I was not prepared for that either. We were trying to collect some faecal samples for gut content analysis and things may have got out of hand (more literally than I like to remember!) Also hysterically funny! Only slight issue is that sunfish poo is bright orange and smells appalling. (I mean no one expects faecal samples to smell good, but this was unbelievable.)

sunfish poo.png

Sunfish poo… to be avoided at all costs!

4.      Although they look smooth, beneath the mucus layer, the skin of sunfish is very rough to the touch so if a flapping fin catches your arm, it’s exfoliating to say the least, like being towelled off with sanding paper.

5.      Sunfish blink. They have a strong white muscle around the eye socket that they can use to wipe the eye or pull it back in if feeling threatened. Bit disconcerting when they wink at you… then shower you with slime/poo/seawater. Nice trick.

sunfish eye.png

Photo on left shows the eye pulled in, protected from the measuring tape and then on the right, the fish peeks out again to see what we are doing… sneakily does it!

6.      They are strangely curious fish, frequently swimming right up to the camera or hovering just under the boat looking up at us. The fishermen sometime use brooms to try push them away and prevent tangling!

Curiouser and curiouser…

7.      Sunfish have a sense of humour. Okay, maybe I made this one up, but I watched Lawrence wrestle a particularly large one into the weighing tarpaulin and get slapped around the face for his trouble by a large fin… slapped by a wet fish!! Needless to say I think the fish won that battle.


Oh my what big fins you have?! All the better to slap you with!

If anyone has seen a stranded sunfish or has more sunfish pub facts, please use the comments section to get in touch or email me: nphillips01@qub.ac.uk, or for further photos and project updates follow me on Twitter: @sunfishresearch or on Instagram: SunfishResearch