//
you're reading...

Biology

Making the best of a bad situation: the upside of squid injury.

Article: Crook, R. J., Dickson, K., & Hanlon, R. T. (2014). Nociceptive Sensitization Reduces Predation Risk. Current Biology, 24, 1121–1125; DOI: 10.1016/j.cub.2014.03.043

BACKGROUND

The ability to feel pain (called nociception) warns us to stop dangerous activities immediately, but the benefit of experiencing long-term pain sensitivity is not as obvious. Prolonged pain in humans causes increased sensitivity and is often paired with anxiety. Many species show increased, lasting sensitivity of defensive responses. This allows prey to react more quickly or more intensely to approaching predators. Observing squid and their fish predators gives an opportunity to test the evolutionary benefits of prolonged sensitivity after sublethal injury. The authors in this paper hypothesized that hypersensitivity to predation stimuli exists to offset an increased predation risk associated with sublethal injury.

squid_black_201893

(Source: www.whoi.edu)

The longfin inshore squid, Doryteuthis (Loligo) pealeii, has long had a place in scientific research- used as a model organism to study axons (nearly 1000 larger than typical mammal axons) and their unique and vibrant camouflaging color changes. Squid have a complex nervous system and can easily be caught near shore so also work well as a study species for pain sensation. Minor injury causes hypersensitivity to visual and tactile stimuli without affecting general activity levels or foraging behavior. The experimental predator of the longfin squid, the black sea bass (Centropristis striata), uses visual cues to find its prey.

 

METHODS 

When faced with danger squid show a predictable series of defensive behaviors in response to predatory approach as shown in Figure 1. The researchers recorded the sequence and scored the behaviors when squid were placed in the vicinity of a black sea bass predator. They compared the timing of the behaviors, distance at which they occurred and the ultimate escape success rate. The research team cut off the tip of one arm of each squid to create sublethal injury without causing impairment to normal functions or locomotion. This small injury induces a state of hypersensitivity of defensive behaviors. Anesthesia was used on some experimental groups to show the result of injury or non-injury without the associated pain and prolonged sensitivity.

CBfig1_Rnd2

Escalation Pattern in Predator-Prey Interactions between Black Sea Bass and Squid. Top: four stages of predator behavior. Orientation is the first change in direction toward a squid from an ongoing swimming trajectory, and the distance from fish to squid is the ‘‘start distance’’ of the predation attempt. Pursuit is an accelerated, direct approach toward a squid, with the fish’s dorsal, pectoral, and caudal fins folded. Attack is close-proximity ‘‘grappling,’’ with the fish’s mouth open and fins extended to facilitate rapid directional changes. Capture is definedas any part of the squid’s body caught in the mouth of the fish. Bottom: defensive responses of squid to the fish. Primary defense (avoiding detection via crypsis) escalates to secondary defenses once the squid is alerted. Crypsis, via chromatophore patterns of disruptive banding while sitting on the sub- strate or all-over beige when swimming, occurs in the absence of encounters and often during early encounter stages; it received an escalation score of0. Distance between squid and fish at the first secondary defensive behavior is the ‘‘alert distance.’’ Secondary defenses were scored based on their typical progression. Deimatic chromatophore displays that distract or startle a predator were scored 1, as were slow avoidanceswimming evoked by distant threat. Escape jetting without inking was scored 2. This typically (but not always) followed expression of behaviors scored 1. Ink release, which was almost always combined with erratic escape jetting, was scored 3. The highest escalation score was recorded for each predatory encounter.

 

 

RESULTS

When faced with fish predators the injured squid showed increased defensive maneuvers. This is particularly important given injured squid were attacked at greater distances than their uninjured counterparts, regardless of presence of anesthesia.

Injured squid, without anesthesia, showed longer distances at which they became alert of predators and showed a flight response. Injured squid, both anesthetized and not, showed reduced survival in an attack. Injured squid without anesthesia, reacting based on prolonged nociception, fared better than the numb, injured squid. After a 30 minute period of attack by a fish predator uninjured (U) squid showed about a 75% survivorship rate compared to close to 50% for injured squid (I) and a significantly lower, less than 25%, chance for injured squid with anesthesia preventing nociception (IA).

 

Fig 3 outcomes

Injured Squid Lacking Nociceptive Sensitization Had the Lowest Odds of Survival. At the conclusion of a 30 min trial with free interaction of squid and fish, squid in the I and IA groups had lower overall survival than in the U group, and IA group squid were most likely to be killed.

 

CONCLUSION AND SIGNIFICANCE

Increased defensive sensitivity due to prolonged feelings of pain allows injured squid to more successfully avoid predators than anesthetized injured squid. Uninjured squid remain in a superior position with fewer attacks and higher survival. This shows the potential importance of feeling pain and reacting to it long-term. The lower attack survival rates for injured squid also remind us of the potential for a large impact from a small injury. Predator-prey interactions helped shape the squid’s reactive abilities when faced with sublethal injury. Though nociception is widespread in the animal kingdom this paper is the first to show increased survival due to pain-induced hypersensitivity.

Sublethal injury is common in all animals and can make the injured prey easy targets for predators.  This research shows that animals can counteract the vulnerability through increasing their defensive efforts.

Discussion

No comments yet.

Post a Comment

Instagram

  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 7 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 9 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 10 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 11 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 12 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com