What is responsible for the "spark" in the ghost knifefish?

The South American ghost knifefish can generate the highest frequency of electricity observed in any animal. Researchers have found that this could be due to an evolutionarily modified sodium channel.

Parapteronotus hasemani, a species of ghost knifefish used in this study

Electric fish produce electrical signals from their electric organs to sense their environment and communicate with others. The Apteronotids (ghost knifefish) use action potentials of specialized cells that originated from motor neurons in the spinal cord to produce electrical signals. Their electric organs exhibit the highest frequency action potentials of any animal, frequently exceeding 1 kHz. They also require no signal from the brain to produce these electrical discharges. The researchers compared genes in electrical and non-electrical fish that encode voltage-gated sodium channels. Sodium channels regulate the number of sodium ions travelling in and out of cells, allowing electrical signals to be generated that regulate cellular functions. Voltage-gated sodium channels open and shut depending on the voltage across the cell membrane. In an ancestor of a group of fish within the Apteronotids, the researchers discovered that the gene that encodes sodium channels in muscle was duplicated.

Image comparing amino acid sequences from Thompson et al. (2018) Rapid evolution of a voltage-gated sodium channel gene in a lineage of electric fish leads to persistent sodium current. 

The gene was able to make sodium channels in the spinal cord throughout the fish's evolution. The motor neurons that control the firing frequency of the electric organs are also located in the spinal cord. The gene also gained a mutation over the fish's evolution that allows the channel to open more frequently, which could explain the electrical organ's high frequency firing.
These sodium channels are only found in the muscles of most animals, so this is a unique characteristic of the ghost knifefish. Sodium channels are often the target of neurotoxins and play a role in several neurological and muscle disorders in humans. Further research on this mutation could help determine the mutations that lead to these disorders in humans.

Male Loggerhead Sea Turtles and Their Breeding Patterns

Figure 1: Male loggerhead traveling inland to breed

A new study from the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio) showed that most male loggerhead turtles go back to nesting beaches to breed, which is a common behavior among female turtles. This study was published in the journal Marine Ecology Progress Series because it breaks the normal paradigm on breeding behavior in these marine turtles and because it also explains how the species itself could also breed in feeding areas or during their travels towards the nesting beaches. The new paradigm that these researches created was that male turtles (Caretta caretta) return to the nesting beachs to breed.

Caretta caretta is a marine species of sea turtle that predominantly lives in tropical and temperate areas around the world. In the eastern Mediterranean, sea turtles nest along the coasts of Greece, Turkey, Cyprus, Libya, Lebanon, and Israel. It was believed before that only female turtles went back to the nesting areas to lay eggs after mating with the male turtles. In the test called philatropic: behavior studies, there is detection, marking, and a genetic study of these female turtles that travel back to the beach to lay eggs.

Figure 2: Female loggerhead laying eggs on a Mediterranean beach

Lecturer Marta Pascual states "Our study reveals the breeding behavior of the Caretta caretta marine turtle to be more complex. In most populations, females turtles are not the only ones with philatropic behavior: males also mate near nesting beaches." To get these conclusions, the UB-IRBio team increased the number of microsatellite markers to analyze gene flow among turtle populations in the Mediterranean area. Their results showed that there was a higher gene differentiation in the nesting beaches in the Mediterranean. This suggested to them that there is a possibility that turtles breed in feeding areas or during their journey towards nesting beaches. Marta then continues to say "Also, if we compare mitochondrial and nuclear markers, we can compare the spreading behavior of male and female turtles in different areas, which shows complex and particular breeding behavior in each area." Philopatry happens in both male and female turtles. There are times though were there is breeding patterns between males and females in locations other than their birth place.

One problem that can factor into this is that breeding behavior can change depending on the population and sexes within the population. The temperature that the eggs are incubated at determines their sex. If the temperature is high, there will only be female turtles when hatching happens. Since the global temperatures are rising, this is causing more females to be born than males, which is upsetting the balance within populations.

Figure 3: Loggerhead sea turtle hatchlings

The ending to this article talked about protecting the species of turtles in the Mediterranean. They said that the genetically differentiated units should be protected. In some cases, the population size is very large, but in most cases, the populations are much smaller. Lastly, they stated that there needs to be more comprehensive studies of different areas to identify bottlenecks and to study the impact of the increase of variability.

Sources:

Universidad de Barcelona. "Male loggerhead turtles also go back to their nesting beaches to breed." ScienceDaily. ScienceDaily, 14 March 2018. <www.sciencedaily.com/releases/2018/03/180314092710.htm>

M Clusa, C Carreras, L Cardona, A Demetropoulos, D Margaritoulis, AF Rees, AA Hamza, M Khalil, Y Levy, O Turkozan, A Aguilar, M Pascual. Philopatry in loggerhead turtles Caretta caretta: beyond the gender paradigm. Marine Ecology Progress Series, 2018; 588: 201 DOI: 10.3354/meps12448

Images from: Google images

Various Pigment Types of Synechococcus Cyanobacteria from Across the World's Oceans

Studies have been done by the University of Warwick that show that bacteria that are crucial to ocean life can shift their color like chameleons to match different colored light across the world’s seas. This is a very intriguing concept, but also very amazing too. It is found that blue light is prevalent in the open ocean (obviously), while green light is prevalent in coastal and equatorial waters. Red light is prevalent in estuaries. The bacteria Synechococcus cyanobacteria contains specific genes that allow it to adapt their pigments to the light sources that are available! Therefore, this bacteria that lives in the open ocean has adapted to take in primarily blue light, whereas the bacteria in estuaries take in red light and bacteria in coastal and equatorial waters take in green light. S. cyanobacteria uses light to capture carbon dioxide from the air and produce energy for the marine food chain. Their genes are altered in such a way so as to thrive in any part of the world’s oceans.

Figure 1: SEM of Synechococcus cyanobacteria

The light that is absorbed is determined by a multitude of factors. One is the tilt of the Earth and the direction of the light from the sun to the Earth. Refraction plays a role to the bending of light. The geography also seems to play into part of the reason as to the light absorbance changes. Blue light is most prevalent in the open ocean, as it penetrates into the deep waters (it is the deepest penetrating wavelength). The prevalence of light changes depending where on the planet you go. In estuaries, says researcher David Scanlan, the light is often red, whereas in warm equatorial and coastal waters, the light is more green. The bacteria have adapted to utilize the changing light intensities to produce efficiently around the globe.

Figure 2: Various pigment types of Synechococcus cyanobacteria from across the world's oceans, grown in culture at the University of Warwick

Scanlan and colleagues analyzed specific gene sequences from S. cyanobacteria in the different water samples from around the globe. What they found was the same genes in bacteria living thousands of miles apart around the globe. The genes are known as “chromatic adaptor” genes, and they are abundant in ocean dwelling S. cyanobacteria which enables “these color-shifting microorganisms to change their pigment content in order to survive and photosynthesize in ocean waters.” If the same bacteria is in the open oceans, warm equatorial waters, coastal waters, and in estuaries, being able to efficiently produce oxygen from carbon dioxide is a useful adaptation. It would be seemingly wasteful to spend more energy in coastal waters or even estuarine waters to photosynthesize blue light if it isn’t the most prevalent light wavelength. The same goes with trying to photosynthesize red light in the equatorial waters, or green light in the open ocean.

Scanlan says that “finding [these bacterial] cells capable of dynamically changing their pigment content in accordance with the ambient light color … gives us a much deeper understanding of those processes essential to keep the ocean ‘engine’ running.” It is understood that paying attention to these microorganisms will help us better predict how the oceans will react in the future to a changing climate with increasing levels of carbon dioxide. If anything, these “key primary producers are potentially excellent bio-indicators of climate change.”

Source for Article:

https://www.eurekalert.org/pub_releases/2018-02/uow-ob022118.php 

Source for Figure 1: 

https://www.sciencesource.com/archive/Synechococcus-Cyanobacteria--SEM-SS2582898.html#/SearchResult&ITEMID=SS2582898 

First Spontaneous Mutant Coral Symbiont Alga Found

Japanese researchers have recently identified the first spontaneous mutant coral symbiont alga that does not maintain a symbiotic relationship with its host. The alga have devised a system where the simple addition or depletion of a nutrient can switch the symbiosis on and off, experimentally. This alga, which is mutant, enables the development of a genetic transformation system. This system will eventually be a powerful tool for researchers studying coral-algal endosymbiosis.

Figure 1. Symbiotic and non-symbiotic state of the sea anemone E.pallida, respectively. 

A great source of biodiversity in the sea is coral reefs. Stable symbiotic relationships between host cnidarian animals and the symbiont dinoflagellate are what the ecosystem relies on. Environmental changes due to globing warming can collapse this symbiosis. An example of this is “coral bleaching”. Understanding mechanisms for maintaining stable symbiosis is extremely difficult.

Figure 2. Coral Bleaching Reference 

The mutant in these coral is deficient of uracil which is a basic compound of nucleic acid. This has appeared to have lost the ability to maintain symbiosis with a model organism. The model organism used in this case is the sea anemone. This is what indicates the simple addition or depletion of the nutrient which can be used as a switch for controlling the symbiotic relationship. The next step in this research is to introduce genetic mutations that are going to be capable of reversing uracil deficiency in the mutant dinoflagellate. This can hopefully provide clues for identifying algal genes responsible for symbiosis.

Source for Article and Figure 1: Tohoku University. 2018. New Mutant Coral Symbiont Alga Able to Switch Symbiosis Off. ScienceDaily. https://www.sciencedaily.com/releases/2018/02/180222103416.htm

Figure 2 Source: 

http://sites.psu.edu/ichen/wp-content/uploads/sites/38297/2016/04/coralbleaching.jpg

Sea Anemones Evolving Toxins May be the Key to Medical Innovation

For years scientists have used the venom from many creatures to create medicines and treatments for various illnesses. To do this, scientists would extract venom from adult animals and then analyze the make up of the venom and use it in various ways. This process has always been done using adult animals, because the thinking was that an animals venom was the same at a larval stage as it would be at the adult stage. But a recent study with sea anemones has proved that theory wrong. Using a species of sea anemone, Nemotostella, also known as the Starlet Sea Anemone, researchers studied the venom development from larva to adult hood and how the venom chemically changes over the span of their developmental stages. Sea anemones being part of the Phylum Cnidaria have stinging cells on their tentacles that inject the venom into their prey called cnidocytes. To study the venom from these animals, researchers cultured these cells in various life stages and looked into the behavior of Nemotostella at each developmental stage.

Researchers began by studying the venom produced by larva Nemotostella. By analyzing the venom and watching the behavior of the larva, they observed that the venom produced at this stage seemed to be used for defense rather offense. As the small larva are floating through the water they are highly vulnerable to predators. The venom they produce helps them fend off predators so that they can grow to an adult. When a predator eats a larva, the larva release highly potent venom which makes the predator spit them out. This helps ensure that the larva can grow to adulthood and eventually reproduce.

Image of Nematosella 

As Nemotostella reaches adulthood its venom changes from that of a defense mechanism, to something to help them catch their prey. The venom chemically changes to better stun and kill potential prey, rather than surprise and disgust a potential predator. While researchers were surprised to find these changes, the changes did not stop with just development, the environment had an impact on the chemistry of the venom as well. As the water salinity, temperature, and food supply changed so did the potency and make up of the venom. This was a completely new aspect of the evolution of the sea anemone that researchers were excited to discover.  

Expression of Nematosella toxins 

The reason that this discovery is such a big breakthrough is due to the potential medical advancements that would be gained from studying the evolution of the Nematosella venom. Because most, if not all, research done on animal venom is venom taken from adult animals, the concept that there is a whole new variety of compounds from venom to look at has researchers thrilled. The possible new drugs, medicines and treatments that could come from studying these new compounds are unlimited. 

Cluster of Starlet Sea Anemones

Another question being asked in the scientific community after this discovery is how "normal" of behavior is it for animals to change their chemical composition as their environment changes? With climate change becoming a major issue around the world, not just for aquatic ecosystems but for terrestrial ecosystems as well, if scientists can study this further then perhaps they can understand ways to help other organisms change and adapt to an environment that otherwise would be lethal for them. This research could help millions of organisms have a brighter future in a harsher world. 

Resources: 

Image 3 : http://www.sars.no/research/SteinmetzGrp.php
Image 2: https://elifesciences.org/articles/35014

Image 1: 

ScienceDaily. Retrieved March 18, 2018 from 

www.sciencedaily.com/releases/2018/03/180305101633.htm


Yaara Y Columbus-Shenkar, Maria Y Sachkova, Jason Macrander, Arie Fridrich, Vengamanaidu Modepalli, Adam M Reitzel, Kartik Sunagar, Yehu Moran. Dynamics of venom composition across a complex life cycle. eLife, 2018; 7 

Hermit crab uses 'walking coral' as home

Hermit crabs are well known for making their homes out of empty shells. They will go from shell to shell throughout their lifetime trying to find the perfect fit and to gain better protection. However, it has recently been discovered that shells are no longer the only objects hermit crabs are using for protection. A species of hermit crab located in the Amami Islands, which is part of a chain that stretches southwards from Japan towards Taiwan, has been found to be using solitary corals for their shelter. This species of crab is named Diogenes heteropsammicola, after the species of coral that they inhabit.

Hermit crab (Diogenes heteropsammicola)

This relationship has proved to be mutually beneficial for both the hermit crab and the coral. By using coral as its protective armor the hermit crab no longer has to continue to search and search for new and better shells as it continues to grow. The space in the coral in which the hermit crab sits grows with the crab, so it does not need to search and compete among its species for new homes. In addition, the coral is able to sting, which helps to further protect the crab from predators such as starfish, larger crabs, and octopi.

A type of coral the hermit crab will use (Heteropsammia cochlea)

This relationship is also able to be favorable for the coral as this species of coral is a solitary coral instead of a reef-building kind. Solitary corals are often found on shallow sandy seabeds. With this type of habitat, the solitary coral runs the risk of being buried by sediment and overturned by strong currents. To combat this, corals will develop a partnership with other animals to assist them out of the sand and do the ‘walking’ for them. This is usually seen with marine worms, but is now prevalent in this hermit crabs species as well.

Coral skeleton after being used by hermit crab

Though more research needs to be done, it is thought this relationship with hermit crabs developed similarly to how the marine worms use the coral for protection. In the case of the marine worm, a young coral will settle on a small shell that has already been colonized by the marine worm. The coral then grows over and beyond the shell, providing a cavity for the marine worm, which is continuing to grow as well. These hermit crabs likely acquire coral shelter and develop this symbiotic relationship in a similar manner such as this one.




Mynott, S. (2017). Newly discovered hermit crab species lives in 'walking corals.' The Conversation, 12 March 2018.

Undersea Constellations: The Global Biology of an Endangered Marine Megavertebrate (Whale Shark) Further Informed through Citizen Science

It is challenging to gather ecological data including behaviors and movements on worldwide animals. Such data is gathered from multiple sources because it would be impossible for one group of scientists to collect such data on such a large spatial scale. One approach that has been helpful is citizen science, the collection of data from the general public, which has helped increase our knowledge on animals that inhabit global spatial scales. With such data we can access the abundance, size, sex frequency, and spatial trends of Nursey sites, mating sites, and feeding hotspots of such animals that can help us to better manage and protect a species. An example of an animal that is of critical importance to obtain such data would include the Whale Shark (Rhincodon typus).

Little is known about the Whale Shark, and the knowledge we have on the animal has been recently documented in the past decade. They filter-feeders that aggregate in groups at specific locations throughout the oceans where there is much Planktonic growth, and are distributed between 30°N and 30°S. Their life history includes slow growth, later maturation, and extended longevity, which makes them vulnerable to population declines especially to human threats including bycatch, pollution, ship strike, and targeted fishing which is why it is critical to obtain such spatial data. Ecotourism activities have focused on monitoring such sharks via photo-identification, observing unique skin patterns, thus creating a database of photo-identified sharks. This study reports the success of monitoring the Whale Sharks on the global scale which includes sightings on local and global levels, size and sex ratios over time, locations of common resighting history, and the resighting of individual sharks in one or more countries. 

Figure 1. Unique pattern behind the gills helps identify individual

Photo-identification images are collected when a tourist or a researcher is swimming and takes a picture of a skin pattern that is unique to each individual shark that are long lasting. An example is seen in Figure 1. Such pictures are then uploaded to a database online as well as other information including sight location, sex, and estimated length. Computer-assisted pattern-matching technology is used to determine if the shark is a new shark or if it is a resighted shark. Each encounter is assigned a location code, depending on the country or hotspot where the encounter, or sighting, occurred. Identified sharks are catalogued with a prefix according to the location code from the first identifiable sighting and each newly identified shark is assigned a unique number specific to that sighting location.

Figure 2. Hotspot Distributions of Whale Sharks

From 1992 to 2014 there has been 28,776 whale shark encounters, and 6091 individual sharks have been identified from 54 countries. The authors of this study determined 20 hotspots, or locations that had at least 100 whale shark encounters, which have contributed to 99% of all the documented encounters. As seen in Figure 2, such hotspots include Belize, The Maldives,  South Africa, Tanzania, Mexico–Atlantic region, Honduras, Mozambique, Qatar, Western Australia (Ningaloo Marine Park), The Philippines (Donsol, Leyte, Cebu), Seychelles, Djibouti, Oman, The United States–Gulf States region, Christmas Island, Mexico–Pacific region, Indonesia, Thailand, Red Sea, and The Galapagos. Much of these sites have been identified with the help of the general public including ecotourism activities. Such sightings have been correlated with areas of high primary productivity of plankton. 

Figure 3. Sex ratio of identified whale sharks at global hotspots

As seen in Figure 3 there seemed to be a strong male bias throughout 14 of the previously mentioned hotspots, with at least 66% of the individuals being males. However, at the Galapagos, 99% of the individuals were female, at the Red Sea, 75% of the individuals were female, and in Thailand, 68.5% of the individuals were female. There is also a bias of the juvenile inhabiting the coastal areas. 

Table 1. Average total length

According to Table 1 the longest individuals occur at the Galapagos with an average length about 11.07 meters, followed by the U.S-Gulf States region with an average length of 8.01 meters, Belize with an average of 7.21 meters, Mexico-Atlantic region with an average of 7.12 meters, and all other locations with an average of 7.0 meters. 

Based on the data, the whale sharks tend to be found in localities throughout the year and some may even stay in the same area for an entire year. However, most Whale shark aggregations are very seasonal in which ecotourism activities try to take advantage of. The overall average of sharks returning to the same hotspot within 2 or more years is about 35.7%.

Based on photo-identification, marker tags, and satellite tracking Whale Sharks tend to migrate between local countries, maybe like 1000 km. There are only very few exceptions where the whale sharks migrated across entire oceanic basins. Not much is known about their reproduction, however, many pregnant females are found in offshore habitats, suggesting such areas provide pupping and nursery grounds.

Citation
Bradley M. Norman, Jason A. Holmberg, Zaven Arzoumanian, Samantha D. Reynolds, Rory P. Wilson, Dani Rob, Simon J. Pierce, Adrian C. Gleiss, Rafael de la Parra, Beatriz Galvan, Deni Ramirez-Macias, David Robinson, Steve Fox, Rachel Graham, David Rowat, Matthew Potenski, Marie Levine, Jennifer A. Mckinney, Eric Hoffmayer, Alistair D. M. Dove, Robert Hueter, Alessandro Ponzo, Gonzalo Araujo, Elson Aca, David David, Richard Rees, Alan Duncan, Christoph A. Rohner, Clare E. M. Prebble, Alex Hearn, David Acuna, Michael L. Berumen, Abraham Vázquez, Jonathan Green, Steffen S. Bach, Jennifer V. Schmidt, Stephen J. Beatty, David L. Morgan; Undersea Constellations: The Global Biology of an Endangered Marine Megavertebrate Further Informed through Citizen Science, BioScience, Volume 67, Issue 12, 1 December 2017, Pages 1029–1043, https://doi.org/10.1093/biosci/bix127
Hyperlink:
https://academic.oup.com/bioscience/article/67/12/1029/4641655
file:///C:/Users/Tyler/Desktop/Marine%20Biology/Whale%20Shark.pdf

King penguins may be on the move very soon

A major issue currently in the marine science world is global warming.  Colonies of King penguins in Crozet, Kergeulen and Marine sub-Antarctic islands may eventually be nothing more than a memory in a few decades.  Global warming could lead to the King penguins moving south or even worse, disappearing completely.

Figure 1. King penguins

According to Robin Cristofari, the main issue is that there are not very many islands in the Southern Ocean and not all of them are conducive to support large breeding colonies for the penguins. As a matter of fact, King penguins are picky animals.  In order to form a colony where they can mate, lay eggs, and care for their chicks throughout the year, they require smooth beaches of sand, no winter sea ice near the island, and temperatures they can withstand year round. 

A trusted and consistent food source is what these penguins are most worried about. These seabirds food source has always came from the Antarctic Polar Front, which is an upwelling front in the Southern Ocean. Because of climate change, this area is moving away from the islands and drifting south.  Therefore, penguin parents have to swim even farther for food while their young are fasting on the shore.  This study predicts that the length of parents’ trip for food will exceed the resistance to starvation of their offspring which in turn, will lead to massive King penguin crashes in population size.  On the other hand, it may lead to relocation, which is what we can hope for.

On the bright side, King penguins have been able to survive crises in the past.  The only difference is that humans are now creating irreversible changes in the Earth system.  The Southern Ocean is now able to be industrially fished. Yet again, the King penguins are faced with another problem and could have an even harder time finding food.

References: University of Vienna. "King penguins may be on the move very soon." ScienceDaily. ScienceDaily, 26 February 2018. <www.sciencedaily.com/releases/2018/02/180226122528.htm>.

Using Drones To Track Sea Turtles

We have been learning about many marine organisms in class.  One interesting question that is raised from all of the learning from this class is: how do scientists keep accurate records for these animals that live within the ocean context?  The answer to this question is that scientists are able to keep track of these organisms through technological advances with time.  Organisms that live on the shore or on land are obviously easier to keep track of because it is easier to visually see what they are doing in their habitats.  However, some species that live within the water are much harder to keep track of.  One of these species includes the sea turtle.  

An article in the Science Daily outlines the technology that scientists use in order to track the everyday life of the sea turtle.  The newest development in technology that scientists are using to track sea turtles is the drone.  In order to keep track of what sea turtles are doing in their natural habitats without disturbing the turtles, scientists are starting to use drones within these marine habitats.

 These drones keep scientists and the general public more aware of sea turtle conservation.  Before scientists started using these drones, they used satellite systems, aircrafts, and observed different organisms on foot.  Although satellite systems and aircraft paved the way toward technology used for sea turtle conservation awareness, they were not always the most cost effective means in providing relevant information for scientists and the general public.  The major disadvantages of using aircraft and observing the sea turtles on foot were that they were slower and demanded a high amount of human labor.  A major advantage of the drones are that they are cheaper and are an overall better tool when collecting information.  

In general, Drones are used to record thousands of hours of pictures and videos of different organisms within their natural habitat.  This reiterates why drones are so advantageous in that they do what no human can do, which is sit in nature with animals for thousands of hours at a time.  This would be especially hard with marine organisms being that humans can only be in the water for smaller periods at a time.  Another major role that a drone will continue to play is assisting with anti-poaching regulations.  Ideally, as technology within the drones progresses, the drone should be able to detect whether there is a person (who should not be there) with the animal population.  In the case of the sea turtles, this would be very advantageous considering they are an endangered species. 

Overall, the use of drones has many advantages within the animal kingdom.  They are specifically advantageous for marine organisms because they can reach hard to get to places and stay there for hours upon hours.  As technology continues to develop, drones will be more useful in detecting poachers within endangered species such as the sea turtle. 

https://link.springer.com/content/pdf/10.1007%2F978-3-319-16178-5_17.pdf

https://www.sciencedaily.com/releases/2018/02/180228085420.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Fmarine_biology+%28Marine+Biology+News+--+ScienceDaily%29

https://www.worldwildlife.org/species/sea-turtle

The Unique Feeding and Reproductive Strategies of the Deep-Sea Dwelling Vampire Squid

       Vampire squid, whose scientific name is Vampyroteuthis infernalis, are a deep-water species that reside in ocean depths from 500 to 3,000 meters. They are passive, soft-bodied animals with a dark red body, huge blue eyes, and a cloak-like web that stretches between its eight arms. Vampire squid have very different feeding and reproductive strategies than all other cephalopod species.


Figure 1. A vampire squid with its cloak-like webs visible

       Typically, squids and octopuses eat live prey, but a 2012 study by Hoving and Robison showed that this is not the case for vampire squid. The researchers showed that vampire squid mostly eat “marine snow” which sinks to the deep-sea from the higher depths of the ocean. Marine snow is a mixture of the remains of microscopic algae and animals, fecal pellets from copepods or krill, and debris from gelatinous larvaceans. The vampire squid eat the marine snow by catching food particles on string-like filaments, drawing the filament through its arms, removing the particles and enveloping them in mucus, then transferring the mucus and particles to its mouth.

Figure 2. A vampire squid surrounded by marine snow

 

       Although this is a very low energy diet, it is able to sustain the vampire squid for several reasons. Vampire squid are neutrally buoyant, and they don’t have to swim to find food since they can just extend their filaments to collect food from the water. For these reasons, the squids have to expend very little energy to stay at a certain depth and feed. Also, vampire squid don’t have to expend energy to avoid predators. This is because there is very little oxygen in the deep-sea, so very few animals can survive, leading to less predators.
       In addition, the reproductive strategy of the vampire squid differs from all other coleoid cephalopods. All other cephalopods reproduce all at once later in their lives in one big reproductive event. The low energy lifestyle of the vampire squid, however, does not support this kind of energy expenditure. Rather, vampire squid alternate between reproductive and resting phases, which is a pattern more common among fish. The squid release about 100 eggs per spawning event for around 100 or so spawning events. These unique characteristics of the vampire squid show how different deep sea-dwelling creatures can adapt and indicate how little is known about the deep-sea.


References: Cell Press. (2015, April 20). Vampire squid discovery shows how little we know of the deep sea. ScienceDaily. Retrieved March 2, 2018 from www.sciencedaily.com/releases/2015/04/150420122828.htm Monterey Bay Aquarium Research Institute. (2012, September 26). Researchers discover what vampire squids eat: It's not what you think. ScienceDaily. Retrieved March 2, 2018 from www.sciencedaily.com/releases/2012/09/120926133239.htm