Many marine species select sites for reproduction based on habitat suitability, environmental tolerances, and oceanographic conditions, in order to enhance development or survival of their offspring. For many species living in the deep sea, it is unknown which factors influence this aspect of the reproductive process. In this study, the occurrence and influences of oviposition site selection were determined for the brown catshark, Apristurus brunneus, and filetail catshark, Parmaturus xaniurus, in the greater Monterey Bay region, providing novel insights into specific habitat preferences and depth distributions. Video footage from the Monterey Bay Aquarium Research Institute (MBARI), and the National Oceanographic and Atmospheric Administration’s Southwest Fisheries Science Center Fisheries Ecology Division (NOAA-SWFSC-FED) was utilized to predict suitable oviposition habitat using MaxEnt presence-only modeling, identify attachment substrates and faunal associations using qualitative observations, and determine depth and habitat preferences using tests of independence and Manly’s selectivity indices. The greater Monterey Bay region was determined as a nursery for both A. brunneus and P. xaniurus on the basis of meeting all oviparous nursery qualifications: high densities of egg cases deposited in the same region, habitat was benthic, oviposition sites were continually used, and no juvenile sharks were observed in the vicinity of egg cases. Complex geographic and environmental features such as rugosity and depth were shown to influence oviposition sites of A. brunneus and P. xaniurus. An increase in rugosity indicated higher predictive habitat suitability. The primary depth range of oviposition sites for both species was 150–199 m, with relatively more A. brunneus egg cases in the 100–149 m range, and more P. xaniurus egg cases observed at deeper depths (200–300 m). Depth ranges for both species are similar and were expanded based on MBARI video observations (A. brunneus = 87–550 m, P. xaniurus = 99–524 m). Areas of greatest predicted habitat suitability were indicated on the shelf break and upper to mid slope of the Monterey Canyon and in adjacent canyons. MaxEnt model output indicated higher induration (i.e., rockier) habitat was the main driver of oviposition site selection. Structure forming marine invertebrates (SFMI) such as corals and sponges were identified as important faunal attachment structures, with egg cases of both species occurring significantly more often on sponges than other substrates. Nurseries are critically important habitat and this research is necessary for influencing habitat-based management. The vulnerability of these and other species prompts further research concerning the use of SFMI as oviparous nurseries for potential essential fish habitat (EFH) designation.
Amber Reichert Presents: Habitat Associations of Catshark Egg Cases (Chrondrichthyes: Pentanchidae) off the U.S. Pacific Coast
Last weekend marked the seventh annual Whalefest celebration in Monterey, California. From ocean mascots and graduate students to one very obedient pup named Obi, the outreach table for Moss Landing Marine Laboratories (MLML) was well staffed all weekend long. For a full set of photos check out the Whalefest photo album on MLML's Facebook Page.
The diversity of sharks, rays, skates and ghost sharks has increased exponentially with nearly 20% of all new species described over the past decade.
Unfortunately, the majority of these sharks and their relatives have largely been “lost” in a hyper-driven media age whereby a few large charismatic shark mega-stars overshadow the majority of shark species, especially during SharkWeek!
While these mega-star’s, such the Great White Shark, receive much media adulation and are the focus of numerous conservation and scientific efforts, the “Lost Sharks” remain largely unknown not only to the public, but also to the scientific and conservation communities.
Please help MLML’s Pacific Shark Research Center to discover and name these ‘Lost Shark’ species. Our Experiment.com campaign is raising funds to do just that.
On December 21st, 2015, another ‘Lost Shark’ was officially found by the Pacific Shark Research Center (PSRC). PSRC is one of the world’s leading labs in chondrichthyan taxonomy research and I had the opportunity of being lead author on the paper for this discovery (how sweet is that?!). For this study, I described a new species of dark-sleek Lanternshark from the genus Etmopterus. And the coolest thing about describing a new species? Naming it!
When I was given that chance, I didn’t hold back. This is the story of how the Ninja Lanternshark got its name.
Let’s begin with ‘Lost Sharks’. The term was created by my professor and co-author, Dr. David Ebert to identify lesser known species that attain little public or scientific attention. Examples of more charismatic species would be Great White Sharks (Carcharodon carcharias) and Whale Sharks (Rhincodon typus). The genus Etmopterus and its 38 species (current to the publishing of this post) are a perfect example of the ‘Lost Shark’ dilemma. That’s because despite being one of the most speciose genera of sharks in the world, it is also one of the least studied. Common names, though not official, are another reflection of the anonymity the Etmopterus genus faces. Names like Brown Lanternshark and Lined Lanternshark are certainly helpful in describing the shark’s appearance but they are not particularly memorable. But that’s not even the main issue! My gripe is with the fact that there are two Brown Lanternsharks (E. compagnoi and E. unicolor) and two Lined Lanternsharks (E. bullisi and E. dislineatus). To be fair, overlaps in common names happen a lot (just Google ‘Yellowtail’ and see how many different species you get). More so, they can even change overtime for a particular species. To avoid confusion, this is why many scientists are far more interested in the universal and permanent scientific name (assuming no changes occur to the status of the species). However, in the case of Lanternsharks, these are deep-sea species people rarely see and therefore rarely talk about. For just a moment, let that sink in- there are 38 relatively unknown species of shark that GLOW IN THE DARK. If that’s not cool enough, they even have spines on both their dorsal fins for protection. So why are spine-wielding Lanternsharks not getting any attention? The answer is certainly up for debate but overlapping common names are certainly not helping. To be fair, there is one more very good reason why common names get so little consideration in taxonomic papers.
Confirming the discovery of a new species consists of hard tedious work that takes a long tedious amount of time…. trust me.
Luckily, in the case of the Ninja Lanternshark, my other co-author, Dr. Douglas Long, has you covered with an easy and exciting read. Delving passed the Ninja Lanternshark, taxonomic research often involves the examination of a much larger picture. For instance, work conducted in the lab of Dr. Gavin Naylor aims to describe the entire chondrichthyan tree of life. Despite the small ripple I was making in the sea of chondrichthyan taxonomy, I still felt like I was a part of a huge moment. I was confirming the discovery of the very first Lanternshark ever found off the Pacific Ocean along Central America.
"What's in a name? That which we call a Lanternshark by any other name would glow as bright." -Sharkspeare
Of equal weight on my mind was therefore the concern that such an interesting discovery was doomed to the ‘Lost Shark’ fate. It was actually Dr. Long who gave me the idea to think innovatively. For a different taxonomy project, he chose the common name Jaguar Catshark, after the fictional shark in the movie, Life Aquatic with Steve Zissou. The decision ended up getting Dr. Long a photo with his new buddy and Steve Zissou actor, Bill Murray, which he has also written about. This isn’t the first time a clever name has received public attention. There is actually a long history of biologists coming up with attention grabbing names, though again these tend to be scientific not common names.
Side note, too cool not to mention: One of my favorite examples is the arachnologist who named a species of trapdoor spider after his favorite singer, Neil Diamond. Stephen Colbert caught wind of this story and had the biologist along with some unnamed spiders as guests on the Colbert Report. By the end, one lucky spider was chosen and named Aptostichus stephencolberti.
As I realized all the potential circling the naming process, I was PUMPED-UP and ready to give this new species a clever name! I should mention that at this point in the story, I had been going to the California Academy of Sciences for months, examining and re-examining my new specimens. I wanted to ensure my specimens were nothing like the other 37 known etmopterids; and they weren’t. These specimens were jet-black with none of the classic body marking that other Lanternsharks possess. They were also much smaller and didn’t seem to glow as bright as most other species. Thinking about a name to reflect those features felt like proof I was almost done.
Almost done? I wasn’t even close.
What if another researcher had stumbled upon some specimens too? At the same time I was sitting in a lab endlessly pouring hours of honed attention into every minute detail of every shark I had, somewhere… someone… could have been doing the exact same thing! It may sound farfetched but the threat was quite real. During background research for the introduction of my paper, I realized new species were being discovered all the time! In 2015, nine new elasmobranch species (included this one) were discovered, with most being deepwater species. When I thought about that, my work became a race against time and a shadow competitor. The first of us to publish would be the official discoverer.
Suddenly, a clever name seemed like a foolish concern. Worst, was the encroaching threat of losing the accolade entirely. My mind was flooded at the time with urgency but haste was its own kind of enemy. It’s not uncommon for taxonomists to write papers proving that what were previously believed as separate species are actually one in the same. One way an error like this occurs is when an established species is mistaken as new because it was found outside its known distribution range. Correcting or preventing such errors is often done through genetic analysis. Looking at the work I had done, I not only had something in a new region for any Lanternshark, I had no genetic analysis. Was I about to make this classic species mistake? Multiple reviews of my work was imperative to assuring my discovery would not be undone …and that takes time.
Interestingly to me, my co-authors did not seem as panic stricken by this cataclysmic, yet still theoretical, threat haunting our research. Why weren’t they more concerned?!?!?!?
Of course, it should’ve dawned on me sooner, it wasn’t their first rodeo. And quite literally so. Dr. Ebert and Dr. Long recently published another elasmobranch discovery from the very same research expedition. Like many seasoned scientists, my co-authors juggle multiple projects in collaboration with many different colleagues. So needless to say, the time-crunch I was feeling was not mutual. In fact, before I was brought onto the Lanternshark project, the specimens had been sitting in a museum for five years; again a common occurrence when there’s many projects to conduct.
Regardless if my “race against time” was as dramatic as I thought, the ‘Lost Shark’ dilemma never changed nor my desire to address it. So how did I find time to come up with a clever name amidst the race to publish our findings?
Turns out, the answer was easier than I thought! I asked four very short people for help. Well… they’re short for now. Since my little cousins are between the ages of eight and fourteen years old, they are literally growing as I type!
I had no idea how successful this approach would be. By incorporating my co-authors suggestions and a little creativity, my cousins and I came up with both a common and scientific name that drew a media storm just in time for the winter holidays! I say this quite literally as my family delayed opening Christmas presents on the 25th so the local news station could finish my interview. Most recently, the Ninja Lanternshark was incorporated in a 10-strip series (beginning here) for the comic, Sherman’s Lagoon by Jim Toomey.
The innovation didn’t stop there. My cousins and I recorded our shark conversation and we created a short film about it. I would now like to introduce you to, “We Named a Shark!” the video of how the Ninja Lanternshark got its name.
And stay tuned for What’s in A Name? Part II: The JAWS Effect, where I delve into the story of the Ninja Lanternshark’s scientific name, Etmopterus benchleyi.
By Kristin Walovich, Pacific Shark Research Center
White Sharks, Manta Rays and Tiger Sharks are easily identifiable to most, but there are more than 1,200 species of sharks, skates, rays and chimaeras, collectively called Chondrichthyans, known to science.
For my Master’s thesis I study a unique group of fish known as ghost sharks, chimaeras or ratfish. They are related to sharks and rays because of their cartilage skeleton, but look quite different. They have large pectoral fins, rabbit-like teeth and a long tapering body (check out an amazing video here). We know very little about these deep-sea creatures, in some cases something as simple as their name.
There are 49 species of Ghost Shark, however several additional species are known to exist, but have yet to be officially named. Under Dr. Dave Ebert, director of the Pacific Shark Research Center (PSRC), graduate students at MLML have named five new species of Ghost Shark since 2006. In fact the PSRC has described 25 new species of Chondrichthyans since its inception in efforts to help the 'Lost Sharks' of our oceans. The most recent edition, the Ninja Lanternshark was officially published last month and received quite the media buzz!
Last year fellow graduate student Paul Clerkin and I traveled to South Africa to search for new Ghost Shark species. For more than 15 years local researchers speculated two new species existed in the region, but no one had taken the time to look for them. It may seem counterintuitive, but a museum is a great place to find unknown species. If researcher or fisherman encounters an unidentified chimaera, it's often placed in the museum collection and forgotten.
We arrived at the South African Museum in Cape Town to gather morphometrics, a series of 96 measurements per animals that we use to describe and differentiate species. Together we measured 90 specimens for a total of nearly 9,000 unique measurements. Finding and measuring specimens isn’t as glorious as it sounds, the specimens are preserved in alcohol and stored in large tubs; one never knows what you might find. It’s a smelly job, but stay tuned over the next few months for several new species of Ghost Shark!
Just in time for All Hallow’s Eve here’s a line-up of the ocean’s most festive Halloween animals! Check them out in all their ghastly horror, they’ve been waiting all year to get some haunting attention.
Halloween Crab (Gecarinus quadratus)
This list certainly could not begin without the arthropod waiting all year for its time to Trick and Treat. The Trick? Halloween crabs are not as beachy as you might think. They spend most of their lives in mangroves and rainforests along the Pacific coast of Mexico down to Panama. Since they have a planktonic larval stage, they only head to the ocean to spawn. The Treat? Racoons love them! Halloween crabs are an important food source in areas where the range of these two animals overlap.
In public aquariums, you might had the privilege of viewing an embryo developing in its egg case watching it grow from a little alien-like body to a fully developed shark or skate.
But, have you wondered how did the aquarists were able to exhibit this without harming the developing embryos? I'll tell you! For my thesis, I have been monitoring the development of a species of skate called the Big skate (Beringraja binoculata). In order to do that, I had to learn how to cut open the egg case, and what better way to learn this technique from than from the experts at the Monterey Bay Aquarium?
The Monterey Bay Aquarium has a popular exhibit where they display embryos developing in an egg case, so I was very lucky to have one of the aquarists, Kelsey Barker teach me how to implement this.
First of all, we need fertile egg cases. Similar to birds, skates can lay unfertilized eggs in their egg cases, but dissecting an infertile egg case is not the best idea as it becomes very messy. This species, the Big skate (B. binoculata) is really interesting, because unlike other species of skates (currently 287+), it is one of TWO species of skates that have the ability to produce multipleembryos within an egg case! How cool is that? All other sharks, skates, and chimaera species produce one embryo per egg case. These Big skate egg cases range from 20 cm to 32 cm in total length (TL).
Once we have a fertile egg, we make sure that the horns of the egg case have opened up. These horns will allow us squeeze trapped air once we enclosed the egg case back up again. This protocol only requires several minutes, we have to take the egg case out to make sure the embryos don't float away! We carefully make an incision with a scalpel on the flat side of the egg case, as it's easier to glue the viewing window. Then using scissors, we cut a square opening in the middle of the egg case.
Once the egg case has been successfully dissected, we dry the outer corners of the square, and use the two most highly 'scientific' items to place the viewing window; super glue and sheet protectors! We wait for the glue to dry and then immerse the egg case back into the water, squeezing any air bubbles out.
Now the egg case is ready to be on exhibit or observed. Here is a picture of my tank setup!
These embryos will fully develop within six to eight months, this is around the time when they used up their yolk sacs, then they emerge out of their egg cases ready to show the world that being a baby skate isn't easy!
Have you ever come across a strange peculiar object that looks like a dried out husk along the beach? Believe it or not, they're not driftwood or anything plant related, but are egg cases!
These egg cases are also commonly known as mermaid purses and vary in shape, sizes, and texture. Species of sharks, skates, and chimeras are know to lay mermaid purses.They are all created internally by the mother, then deposited on the sand floor or wrapped around kelp.
Most of the time, they end up washed up on shore, with nothing in them. Now, you may wonder, what is actually in mermaid's purse? Instead of giving live birth, these oviparous (egg-laying) species of sharks, skates, and chimeras, have found a method of producing offspring limiting the gestation period inside the mother. The eggs are internally fertilized in the female, this is also how the egg case is formed. The egg case is made of keratin, similar to the material from our hair and fingernails, the mother lays the egg case near kelp or on the sand camouflaging the egg case.
Inside there is a tiny embryo waiting to become a shark, skate, or chimera! These embryos are left to fend for themselves as soon as the mother deposits the egg case. Once placed in the perfect environment, the embryo will stay in their egg cases from three to 18 months, even longer, depending on the water temperature. After using up their yolk sacs, these embryos wriggle out and are ready to take on the next step of their lives! Interested in learning how aquariums manage to make a viewing window in an egg case? Click here!
As an early career scientist, I am still learning about what it means to be a shark expert and the standards by which we uphold these individuals to. Before starting school at Moss Landing Marine Laboratories, I used programming similar to Discovery Channel’s Shark Week or NatGeoWild’s SharkFest to help me define those terms and build my knowledge of “shark facts”. Did you make the same mistake?
How would you define a shark expert?
There was a time when I thought the title of shark expert was akin to a person's scholarly credentials. Discovery, NatGeoWild and similar networks have all taught me otherwise. I used to mean that as a compliment. At first, it was intriguing to learn how people from different walks of life could end up becoming shark experts in their own rights. In my opinion however, the term “Shark Expert” quickly de-evolved leaving the accolade vacant of respect, saturated in melodrama, and a burning question
… how do these programs define a shark expert?
The Modern Day Shark Expert.
The modern day shark experts have gotten their starts from a myriad of different paths. Yet whether their credentials are rooted in science, diving, surfing, fishing, or just knowing waaay to much about shark attacks, those individuals lack a different kind of diversity. In the scientific community at least, I know there are plenty of women and people of color who study sharks. I just wouldn’t know that from watching TV.
With regards to women scientists, take a look at the group the Gills Club. Their sole focus is to connect girls and young women with female shark scientists. That’s it. Through their quest, they have encountered so many well qualified female shark scientists that they have been able to develop a newsletter featuring two new female shark scientists every month. Do you see where I’m going with this?
There are plenty of well qualified female shark experts!
The biggest fish to get fried last year were mockumentaries! These confusing pieces of… fiction are now completely absent in this year’s programming! Fans were also vocal about the shows they felt Shark Week did right and as a result, Alien Sharks is back in 2015 with a third installment.
I couldn’t find a single female shark expert for the 2015 shark programming.
Though the programming is already underway for 2015 there is still work to do. For instance, the descriptions for this year’s shows are absent of any female names. It may be too late for 2015, but 2016 could be the year for a more diverse representation of shark experts!
So here is what I propose!
Watch Shark Week. Watch Shark Fest.
In doing so, support the shows that push shark programming in the right direction by featuring a diverse representation of shark experts and of course, lots of super sweet sharky science facts! (Say that five times fast. Because it’s fun.)
Not sure which shows you want to support?
Wildlife biologist, Shelley Davis and the Ocean Research Foundation have you covered with these great #WhatToWatch infographics. Inspired by previous guides designed by the now defunct, Upwell organization.
Demand a more diverse representation of shark experts!
I’m happy to see a return this year to shark experts with science backgrounds. Even better is that many of these experts were speaking on the true diversity of sharks and sensationalizing real facts rather than hyped-up fears.
Shark + Expert = Sharxpert!
#sharxperts and #diversifyURsharxperts
(I will make this a thing! Just waiting for it to catch on…)
In hopes of a change in 2016, give a shout out to your favorite #FemaleSharxpert!
If Shark Week and Shark Fest are having a hard time finding qualified female shark experts, then let’s make it easy for them!
But why stop there?
Shark experts come in many shapes and forms with a variety of specializations. In fact, did you know most “shark experts” don’t even refer to themselves or their colleagues as such? That’s because most “shark experts” see themselves first as geneticists, ecologists, divers or fisherman; in other words, as experts in their true fortes. As a result, the field of “shark experts” is huge …like Megalodon huge, or even better it’s whatever ATE Megalodon huge!
Consequently, shark fans deserve more from television networks and a chance to see the real diversity that lies within the field we’ve all come to know and love as, the Shark Expert.
To get you started, here are just a few Sharxperts and labs whose specialties and/or backgrounds are a great introduction to the diversity in shark science!
Andrew Nosal studies shark movements in Southern California.
Gibbs Kuguru uses genetics to study Smooth Hammerhead sharks in South Africa.
The Pacific Shark Research Center consists of a diverse group of graduate students lead by their professor, Dr. Dave Ebert in the study of lesser known chondrichthyan species dubbed, the Lost Sharks.
Kara Yopak, is an expert on shark brains and how they evolved.
Andrea Marshall aka the Queen of Mantas proved that the Giant Manta represents two different species.
Lisa B. Nathanson collaborates with shark fisherman to collect valuable data on shark biology.
On January 25th and 26th, the Monterey Fisherman’s Wharf held its 4th annual Whalefest event to celebrate the migration of grey whales. Thanks to the efforts of fellow Pacific Shark Research Center (PSRC) student, Kristin Walovich, the PSRC and Friends of Moss Landing Marine Labs, hosted a booth at the event, speaking to attendees and passersby about what Moss Landing Marine Labs is all about!
Table attractions for the PSRC included a dehydrated Mako shark head and shark fin from our museum collection, and an anatomical model of a great white that allows you to see the inside of a shark. An interactive matching game, created by PSRC student Jessica Jang, was another favorite allowing people to test their shark knowledge by matching a shark to its description and name. We also showcased a story done by Central Coast News, interviewing PSRC director, Dave Ebert, about the lab’s role in international shark research.