Marine Animal Consciousness 1

Running Head: MARINE ANIMAL CONSCIOUSNESS

Determining Consciousness in Marine Animals

Vivian Slye

Glen Allen High School

I. Introduction

The ocean has always been an elusive figure to human kind in the past, it’s vastness and

depth difficult to comprehend. Even though the planet is composed of 80% water, there has

always been a clear separation between life on the sea and regular daily life inland. And the

creatures that live beneath the surface have always seemed far removed from the furry, powerful,

and well known land animals. But why is that? Why does humanity seem to hold a higher

respect for land locked animals, choosing to more heavily protect them with various rights, laws,

and policies, and believe aquatic life forms to be inferior? Do humans have more of a

connection with land animals simply due to proximity or is it actually because they see a likeness

within them, a conscious awareness of themselves and their surroundings that is hard to perceive

in the creatures of the deep? Many scientists have dedicated their lives to discovering these

answers and with their research comes numerous studies that touch on countless related topics.

But yet all have the common goal of determining how consciousness can be seen in animals, and

if that consciousness extends to animals of the marine variety. Through the research and studies

showcased, consciousness and sentience can be determined in specific species of fish and marine

invertebrate if they share certain anatomical and behavioral characteristic as seen in both

mammals and humans.

II. Brain Structure

While there is no denying that marine animals in total have a startling different anatomy than

terrestrial animals, there are a few significant similarities among these species that could

preclude a form of sentience and consciousness. For example, the brains of land mammals,

marine mammals, and the majority bony fish are divided into three regions: the forebrain,
 Marine Animal Consciousness 3

midbrain, and hindbrain. While the hindbrain controls most automatic functions like heart rate,

breathing, and digestion, and the midbrain deals most with vision (Kotrschal, Van Staaden, &

Huber 1998). But the most relevant part of the brain in regards to the establishment of

consciousness is the forebrain which manages voluntary movement, physical feeling and pain,

and even includes a hypothalamus and pituitary gland which is the central location for hormone

release and emotional activity (Kotrschal, Van Staaden, & Huber 1998). Octopuses, while

having very different brain structure, have been found to have both an endocrine and nervous

system, which is beneficial for those with the belief of marine animal consciousness (Godfrey-

Smith 2017).

Unfortunately, though, for both of these animals, in regards to brain size to body mass or

even the size of the brain in comparison to the size of the brain cavity, results do not look

promising. Both fish and octopuses have a significantly smaller brain in comparison to their

bodies, and some fish have even been found to have brains that only take up 6% of their brain

cavity (Kotrschal, Van Staaden, & Huber 1998). And even though brain size in no way directly

correlates to intelligence or emotional capacity, these findings are less than favorable. Other

aquatic creatures, like crustaceans, also have endocrine systems, however, they do not release

any sort of hormone related to reward or pain, and also their brain and brain stem are combined

into organ called a ganglion (Gordon & Green 2018). But findings are even more unsatisfactory

in relation to consciousness when it comes to species like jellyfish and coral. These creatures are

more related to protists and plankton than other nektonic animals because they don’t have brains

and primarily just drift with the tides (D'mello 2016).

As far as determining consciousness through anatomy is concerned, there are various

elements that are shared between humans, mammals, and marine life, but the most likely
 Marine Animal Consciousness 4

precursors for sentience would be a sign of a forebrain and within a hypothalamus and endocrine

and nervous system.

III. Pain

Even though pain is not an experience any animal enjoys, pain does have a practical purpose.

Because pain is an effect of damage to the body, it informs the animal that something is wrong

and needs to be fixed or is used as a punishment for the prior behavior. And some scientists

believe that the ability to feel pain may be a precursor to sentience. While pain is often

considered to be a physical symptom, it is actually only processed in the brain. The damage

itself may be physical but pain itself is more psychological, as the signal for the damage in

processes in the thalamus and then a new signal is released with the inclusion of pain into the rest

of the forebrain (Kotrschal, Van Staaden, & Huber 1998). The anatomy for this effect is the

same in both land mammals and bony fish, yet the question remains: do the fish feel this pain

physiologically or is this simply just an unconscious negative reaction to a stimulus?

While all animals can respond to a dangerous or damaging stimulus, usually by quickly

maneuvering away or limited movement of the injured area, that does not correspond to feeling

pain. The ability to understand that damage has been made is known as nociception, which

differentiates from pain as pain is solely a physiological affect that takes place in the brain while

nociception is a nerve response at the scene of the injury (Yue 2008). “If one were given local

anesthesia before a dentist extracted a tooth, one’s nociceptors—nerve fibers that produce the

sensation of pain when they are stimulated by tissue-damaging or noxious stimuli—would

respond to the tissue damage, yet the feeling of pain would be blocked” (Yue 2008).
 Marine Animal Consciousness 5

So how can it be determined that fish do in fact feel pain? Well according to Balcombe, and

well known marine biologist who wrote an extensive book on the consciousness of fish, the

neuroendocrine system is “virtually identical in bony fish and in mammals” (2016) thus meaning

that the same anatomy that proves to us that land mammals can feel pain is also present in bony

fish as well as other marine creatures. However, much more compelling evidence for the proof

of pain are the various studies that taken place that not only measure a fish’s pain response, but

also that these animals remember these experiences in later trials and thus try to avoid the

negative stimulus therefore meaning that they could experience long term memory as well.

IV. Memory

Fish are notoriously known for having a “three second memory”, but this is surprisingly

incredibly inaccurate. In humans, memory is mainly controlled by the hippocampus, but this is

only one stop on the neutral network called the Papez circuit which also includes mammillary

gland, the thalamus, and the basal forebrain which all have to do with higher functioning and

cognition (Pressman 2017). In relation, the brain of a fish does not contain all of these individual

aspects, however, they do have a somewhat condensed version located in their forebrain which

allows them to form new memories as well as recall old ones (Balcombe 2016).

According to a study done by the University of Michigan in which snappers were fed both

normal and dyed sardines (Balcombe 2016). At first the only difference in the sardines was their

color, and the snappers did not seem to have a preference between the two. However, then, some

of the red dyed sardines were laced with stinging medusa tentacles which caused the snappers

pain (Balcombe 2016). Very quickly, the snapper learned to avoid all of the red sardines, and
 Marine Animal Consciousness 6

continued to shun them for weeks after, even though they were no longer laced (Balcombe

2016). This study not only highlights the snapper’s ability to feel pain, but they also

remembered events from weeks previous and acted on those memories, creating a learned

behavior and proving that they can be conditioned much like a dog can learn to sit on command.

In an experiment which showcased this run by Dalhousie University in Nova Scotia, giant

pacific octopuses were handled by both a “nice” keeper who fed them and a “mean” keeper who

touched them with an uncomfortably bristled stick, both of who were dressed in the same

uniform (Godfrey-Smith 2017). After only two weeks, the octopuses began to reacted negatively

when approached by the “mean” keeper, scooting away, shooting ink, or spraying them with

their siphon, while they would actively move towards the “nice” keeper to receive food or to

play, and continued to act differently to each one for months following (Godfrey-Smith 2017).

This experiment concluded that octopuses not only have the ability to remember events from

months previous but they can differentiate between humans meaning they have facial

recognition.

V. Communication

While it is fairly easy to understand the structure of the brain in many species to see if they

have the different aspects that seemed to be required for sentience. However, the matter

becomes much harder to study and prove sentience when it comes to the behaviors of these

animals, predominately including versions of communication. For the most part, fish

communicate through pheromones which are a type of hormone they can “smell” in the water.

However, interestingly, there was a study done with fathead minnows were different groups of
 Marine Animal Consciousness 7

minnows either had a schreckstoff of a predator released in the water, or were never taught to

fear that predator. When both groups were placed in a tank together, the experiment showed that

the minnows were more likely to react in fear if they saw other minnows acting the same way

than if they smell a schreckstoff, thus meaning they were more likely to trust other minnows than

simply only trust themselves in regards to fear, much like humans (Balcombe 2016).

While pheromones are the most common use of language in the marine world, recent studies

have found that different types of dolphins actually use their squeaks and whistles as a basic

form of language, one that has actually been recreated in part by human scientist (Abumrad

2014). Through the use of an electronic box, the scientists can mimic the whistles of the

dolphins perfectly and have even been able to call the dolphins names, in their native tongue of

course, and gain recognition (Abumrad 2014). This is a major breakthrough in the marine

biology world because this could give the scientists the leg up they need to form a bond of trust

with these animals which would highly benefit future study.

VI. Conclusion

In this paper, various aspects of marine animal anatomy and behavior were discussed in the

attempt to determine if marine animals have consciousness and sentience. Despite the numerous

evidence and sources regarded during this investigation it is unequivocally decided that

consciousness is an allusive subject that is contemplated by biologists and philosophers alike,

therefore any there cannot be any concrete decision based solely on the research down above.

However, it can be deduced that the likelihood of consciousness can be enormously increased if

the species in question possesses a forebrain with various anatomical aspects that function in the
 Marine Animal Consciousness 8

same regards as a thalamus, hippocampus, and neuroendocrine system. Therefore,

simultaneously increasing the likelihood of the species portraying various behaviors such as

memory, pain, and communication.

Works Cited

Abumrad, J. (2014). What do dolphins talk about. Radiolab. Podcast Retrieved from

http://www.radiolab.org/story/what-do-dolphins-talk-about/

Allen, C., & Trestman, M. Animal consciousness. (2017). In The Stanford Encyclopedia of

Philosophy. Retrieved

from https://plato.stanford.edu/archives/sum2014/entries/consciousness-animal/#toc

Bekoff, M. (2000). Animal emotions: exploring passionate natures: current interdisciplinary

research provides compelling evidence that many animals experience such emotions as

joy, fear, love, despair, and grief - we are not alone. BioScience, 50, 861-

870. https://doi.org/10.1641/0006-3568(2000)050[0861:AEEPN]2.0.CO;2

D'mello, B. (2016). How do jellyfish function with a heart or brain. Science ABC. Retrieved

from https://www.scienceabc.com/eyeopeners/jellyfish-function-without-heart-

brain.html

Godfrey-Smith, P. (2017). The mind of an octopus. Scientific American. Retrieved

from https://www.scientificamerican.com/article/the-mind-of-an-octopus/

Gordon, J. & Green, J. Crustacean. (2018). Encyclopedia Britannica. Retrieved

from https://www.britannica.com/animal/crustacean/Form-and-function-of-internal-

features

Kotrschal, K., Van Staaden, M. J., & Huber, R. (1998). Fish brains: evolution and environmental

relationships. Reviews in Fish Biology and Fisheries, 8, 373-408.

https://caspar.bgsu.edu/~lobsterman/Page/Papers/1998KotVanHub.pdf
 Marine Animal Consciousness 10

MacDougall, R. (1914). The distribution of consciousness and its criteria. The American Journal

of Psychology, 25 (4), 471-499. http://www.jstor.org/stable/1413287

Panksepp, J. (2005). Affective consciousness: core emotional feelings in animals and humans

[Abstract]. Elsevier, 14 (1), 30-80. https://doi.org/10.1016/j.concog.2004.10.004

Pressman, P. (2017). Guide to the anatomy of memory. Verywell Health. Retrieved from

https://www.verywell.com/anatomy-of-memory-2488705

Yue, S. (2008). An hsi report: fish and pain perception. Humane Society International. Retrieved

from http://www.hsi.org/assets/pdfs/hsi-fa-white-papers/fish_and_pain_perception.pdf