There are many ways in which to defend yourself against predation, where the main bulk of my posts have been about self-pursued protection either actively, by force for example (eg. Mantis shrimps), or passively, through camouflage (eg. Cephalopods). However, the ultimate defense mechanism can be said to be one that involves altruism, where your active participation is limited close to none. The altruistic behavior I will talk about in this post is in the form of parental care, seen in the deep sea octopus (Graneledone boreopacifica). They demonstrate the most sacrificial parental care where their progeny survival outweighs their own, this to the extent where the parents consistently dies of starvation as they protect their genetic heirs (Ed Yong, 2014).
Parental care is rarely seen so extreme (Ed Yong, 2014). Usually, energy expenditure is also allocated to future prospects of reproduction and not only to current reproductive status (Kolliker et al 2012, pp. 41), meaning most of the energy acquired goes into self-maintenance to ensure future reproduction. However, these deep sea octopi only reproduce once, whether this is a result of the altruistic behavior or the altruistic behavior a result of its reproductive behavior is not well discussed in the scientific literature. Although ensuring all progenies survive the egg life cycle does have a significant increase in ensuring your genetics are passed on to the next generation, which is ultimately the motivation for reproduction, to starve in order to make this assurance is quite extreme. Could there not be a middle path to take between complete sacrifice and no parental care? There is the possibility that the starvation is to avoid attracting parasites and predators because of debris from eating. Additionally, it is thought that octopi generally cease or greatly reduce consumption after their initial brood have hatched (Robison et al 2014). Therefore, Robison et al (2014) proposed, the starvation seen in boreopacifica might be a result of weighting an increased brood size when hatched (by lengthening the caring time) to a short life with starvation in the cards anyway. Which is yet another evidence that supports the incredible intelligence these creatures have, and is why there should be conducted more research into understanding them.
Figure 1: Image of a deep sea octopus protecting her eggs in her lair (Picture by Stuart Westmorland/Corbis).
It saddens me to say that this will be the last post on this blog, however, here are some honorable mentions that did not make the cut. Use these videos, and the posts I have produced in this blog to inspire you to give back to the sea for what life it has allowed us to make on this Earth.
Some honorable mentions
The Porcupine fish
Similar to the Pufferfish
The flying fish
The electric eel
Technically a riverine species and not marine.