Explaining Science – crustacean symbionts with sea anemones

Explaining Science – a new series of blog posts bringing scientific discoveries focused around biodiversity to your living room.


Are you ready to learn about phylogeography, population genetics and symbiosis, great topics to impress your boss and co-workers at the next Holiday party?

Let’s set the scene: If you have been scuba-diving off the coast of Florida you are probably familiar with the coral reefs found offshore from the coast, the only living coral barrier reef in the continental United States and the third largest coral barrier reef system in the world. It is a hotspot for biodiversity, meaning that you were probably awed (if you looked closely) by the diversity of animals that call this reef their home. Given the large diversity, not only of species but also in strategies that allow them to be successful in this environment, coral reefs are great places for scientists to study relationships among living beings. We refer to this part of science as phylogeography, the study of why species live where they do, how they got there and how they are related with each other.

Here at the MBD we are lucky to have the Laboratory of Marine Invertebrate Diversity led by Professor Meg Daly and her students who explore biodiversity of sea anemones and the diversity in marine symbioses of crustaceans with some anemones. Benjamin Titus, one of the PhD students in Daly’s lab, recently published a study entitled “Specialist and generalist symbionts show counterintuitive levels of genetic diversity and discordant demographic histories along the Florida Reef Tract” in the scientific journal Coral Reefs. I was intrigued and asked Ben to explain the purpose and the significance of his study. Following is a series of clips from my interview with Ben or you can scroll down to a brief take-home-message, summarizing the main results.

  • Introduction: Every good scientific study tests a hypothesis that developed from previous research, here Ben tests these two hypotheses:

 

One of these hypotheses, the specialist-generalist variation hypothesis, predicts that specialists, species that rely on a close association with one particular species, show reduced genetic variation and genetically structured populations.

 

  • Study site: Map of coral reefs sampled along the Florida Reef Tract

Ben collected samples along the Florida Reef tract:

 

  • Study system: Crustaceans living with sea anemones are small animals, many have not (yet) been studied closely. Thus we often do not even know how many species exist within a genus. It is not surprising that genetic analyses reveal new relationships. Ben’s study subjects are 1 sea anemone and 6 crustacean species:
corkscrew sea anemone Bartholomea annulata

corkscrew sea anemone Bartholomea annulata

At least 6 species of crustaceans can live symbiotically with sea anemones. Ben focused on the corkscrew anemone, Bartholomea annulata, as a host for red snapping shrimp (Genus Alpheus), the Pederson cleaning shrimp (Genus Ancylomenes), the spotted cleaner shrimp (Genus Pericilemenes), the sexy shrimp (Genus Thor), and the arrow crab (Genus Stenorhynchus).

These species differ in their life history strategies, what they do to strive and survive:

The red snapping shrimp is most often found buried in the sand beneath the anemone’s column; it is considered an obligate symbiont, because it depends on the anemone for survival.

The Pederson cleaning shrimp is commonly found within the anemone’s tentacles; it is also considered an obligate symbiont but a host generalist, in that it will associate with a variety of anemone species.

The spotted cleaner shrimp lives among the tentacles of several species of sea anemones; like the Pederson cleaning shrimp, it is an obligate symbiont and host generalist.

The sexy shrimp is a generalist symbiont found with a variety of anemones and corals; it is a facultative generalist, for whom a close relationship with an anemone is not necessary for its survival.

The arrow crab is a facultative symbiont, often living in association with an anemone, but such a relationship is not necessary for its survival.

  • Sample collection: Collecting crustaceans for the genetic analysis required a couple of field trips to Florida, scuba-diving offshore and occasionally an inventive technique to knock-out pesky invertebrates.

 

  • Genetic Analysis: Back in the lab at OSU Ben extracted genetic material, specifically mitochondrial DNA, from the samples he collected in the field and for this study used one particular marker within this mitochondrial genome: CO1.

 

  • Results – hypothesis 1: Against his expectations (recall the specialist-generalist variation hypothesis from above), Ben found that specialists showed greater genetic diversity than the two generalists he studied and overall the sampled populations are not structured along the Florida Reef Tract.

 

  • Cryptic species are individuals within a species that are morphologically similar, appear identical, but do not breed with each other because they are genetically quite distinct. Crustaceans living with sea anemones are small animals and many have not (yet) been studied closely. Thus we often do not even know how many species exist within a genus. It is not surprising that genetic analyses reveal new relationships. Based on his previous research findings, Ben suspected cryptic species in some genera, and found evidence  both within the snapping and the cleaner shrimp (genera Ancylomenes and Periclimenes). Ben discovered species that had so far been unknown to us.

 

  •  Results – hypothesis 2: The second hypothesis regarding shared diversification by co-occurring species, was not supported by the collected data. Most populations did not show a recent expansion since the last changes in sea levels with the end of the ice age some 15,000 years ago. Only one of the snapping shrimp species, Alpheus immaculatus (Fig.6b), showed an increase in population size about 300,000 years ago.

 

  • Conclusion: So what do these findings mean? Finding new species highlights that the Florida Reef Tract is a biodiversity hotspot, currently maybe even underappreciated because not all species within this diversity have been detected and described yet.

Understanding the genetic structure of crustacean populations is important because they play fundamental roles in the marine ecosystem, in symbiotic relationships with anemones and corals, the building blocks of coral reefs.

 

Take-home-message: The Florida Reef tract is an important biodiversity hotspot with yet undescribed species. Specialists may have greater genetic diversity than generalists in some, particularly marine ecosystems, where larvae disperse far distances. When host availability is not a limiting factor, species that co-occur on the same host and would be expected to show similar diversification patterns, species may follow quite different trajectories of phylogeographic history.

Citation:

Titus, B. M., & Daly, M. (2016). Specialist and generalist symbionts show counterintuitive levels of genetic diversity and discordant demographic histories along the Florida Reef Tract. Coral Reefs, 1-16.

Did you know that …

Biodiversity refers to the variety of living beings on our planet. Invertebrates are estimated to have the greatest diversity among all animals. The famous biologist and author E.O. Wilson estimates the total number of existing species close to 7 millions (only ~20% of these have actually been described) in his recent book Half-Earth – a great read if you are interested in finding out what it takes to preserve the diversity of animals and plants on planet Earth.

Sea anemones are animals and they are close relatives of jellyfish and corals, all members of the phylum Cnidaria. You may know anemones for their close relation with clownfish, the small orange, black and white fish that make their home within the sea anemones’ tentacles. But these are not the only symbionts living with anemones; some species of crustaceans also use the tentacles for protection.

Symbionts are animals or plants that live closely together. In mutualisms, the symbionts each benefit from this close proximity. For example, clownfish clean the anemones of parasites, the stinging tentacles of the anemone provide protection to the clownfish – watch some clownfish in their sea anemone habitat during your next visit at the aquarium at the Columbus Zoo!

Some symbionts only exist with one particular other species, these are called host specialists. Other symbionts can live with a wide range of species, you guessed right, these are called host generalists.


 

About the Author: Angelika Nelson is the social media manager at the Museum of Biological Diversity, here in an interview with Benjamin Titus, PhD candidate in Meg Daly’s Laboratory of Marine Invertebrate Diversity at the Ohio State University.

Double Treat: a tale of one donation & two collections


Many kinds of mites are associated with insects. Some feed on the insects, while others just hitch a ride. When you work in an insect collection it is not uncommon to find tiny mite “guests” attached to the bodies of our specimens.

As described in a previous post in this blog, when the OSU Acarology Collection acquired the Asher E. Treat Mite Collection, they received a large number of boxes containing slide-mounted mites and a few oversized Schmidt boxes packed with dry mounted moth specimens. The mites were originally collected on (or in!) these moths.

Asher Treat wrote a whole book about mites and the moths they associate with. Like the mites in the Treat collection, the moths are research vouchers, the specimens that Treat referred to (and even illustrated) in his publications.

As with all research voucher specimens, the Treat moths need to be properly preserved for the future and, when necessary, made available to scientists who might want to examine the specimens. As the Triplehorn Insect Collection is a well-known public research voucher repository, we were asked to hold the Treat moth vouchers. At the time we received them from our colleagues in Acarology, we posted some images in the collection’s Facebook page.


The first stop for the Treat moths was the insect collection -40°C freezer. The extreme cold kills any potential pests that might be hiding with the incoming specimens. These pests, things like carpet beetles (dermestids), eat dead, dried insects, reducing them to a pile of dust. So it’s essential that we do not introduce them into the collection! Later on we gently moved all the moths (and/or pieces of them) to our regular storage trays and drawers. Many of the specimens did not have individual labels attached to them. So to avoid confusion, we transferred the specimens to new trays, but kept them in the exact same organization used by Treat. This whole process took several weeks.

During the initial curation we noticed that many of the moths had detailed labels, including the number and kinds of mites removed from them. Some even mention that they were photographed for a publication. However, other specimens don’t have much information associated with them at all. It’s not clear if those are research vouchers or just regular specimens that Treat had in his collection but did not use for publication.


As we curate the collection further, the confirmed research vouchers will receive voucher labels (green, makes it easy to see them in the collection) and a unique identification number. The specimen label data will be digitized and added to our online database, and finally the specimens will be stored according to the moth group (family, genus, species) they belong to. Besides the specimen label data, we will eventually have images of all vouchers specimens.

I am hoping that as the Acarology collection completes the curation and digitization of the Treat mite specimens, we will have answers to some of our questions regarding the voucher status of the specimens. And since we share the same database platform, xBio:D developed here at the Triplehorn collection, we will be able to easily associate the mite specimens with their moth hosts.

The curation of the Asher Treat moth voucher collection will demand many more hours of work by our student assistants and volunteers.

Sunset Moth in the Treat collection.

Sunset Moth in the Treat collection.

If insect curation is the kind of activity you think you would like to learn (or maybe you’re already an expert?!), come talk to me! Volunteer some of your time and talent to help us make the Treat moth vouchers available to the world. Volunteers make a tremendous contribution to the collection and, therefore, to science.

If volunteering is not your thing, maybe you will consider making a donation to the C.A. Triplehorn Insect Collection Friends Fund (#314967). Your gift will revert 100% to the collection and support the dedicated students & interns that work in the collection while getting trained to become the biodiversity scientists of the future. Thank you for your interest!

About the Author: Dr. Luciana Musetti is an Entomologist and the current Curator of the Triplehorn Insect Collection.

A Museum’s Role in De-Extinction

When you think of bringing back a species that is extinct, you may picture a huge Woolly Mammoth or a giant Tyrannosaurus rex. But have you ever pictured bringing back a plump, dove-like bird, the Passenger Pigeon? It seems a highly unlikely candidate for the de-extinct research being conducted by Long Now Foundation’s Revive & Restore. This group of geneticists are working on what they call genetic rescue, to both save highly endangered species and bring back extinct species. But what role do museums play in the de-extinction of a species that died out in 1914?

Cream colored passenger pigeon egg

Passenger Pigeon egg from the Tetrapod Collection © Hothem, 2016

Why Bring Back the Passenger Pigeon?

Imagine a sky darkened for hours because a cloud of birds are passing through a town on the way to their roosting spot. Though an amazing sight to behold these birds were actually quite damaging to the forests they used as a roost. Branches would break under the weight of nests and birds. Feces would cover the trees and ground and cause a rise in acidity in the soil. Scientists Ellsworth and McComb (2003) suggested that about 8% of the forests within the pigeons’ breeding area were damaged annually.

While all this sounds terrible for the forest, the birds were also aiding in the creation of a healthier forest. How? The damage they caused to the forest canopy, allowed more light to enter the forest. The feces they produced would actually add some nutrients to the forest floor creating nutrient rich soil. In addition, their main food source, various nuts from oaks and beeches, were able to spread throughout the Passenger Pigeon’s breeding range creating some of the various forest we walk through today.

Revive & Restore’s overall goal in de-extinction of the Passenger Pigeon is to fill the lost forest disturbance niche that the pigeon’s extinction caused. Researchers debate that by bringing back the pigeons the need for human managed forest fires or disruptions will be decreased. They hope to create more natural forest regeneration via the pigeon’s destructive behavior.

Drawer filled with passenger pigeon study skins

Tray with Passenger Pigeons ©Hothem, 2016

A Museum’s Role in De-Extinction

Museums, like vast libraries of natural history, hold the key for groups like Revive & Restore. Museum collections, such as the Tetrapod Collection here at OSU, are the final resting places for extinct species. Study skins hold the genetic material that researchers need to understand what genetic components are necessary to bring back or understand the evolution of a species. It is part of our mission to make sure that these species are understood not just in terms of location and date but also in terms of their genetic makeup or DNA. Using museum specimens for DNA sequencing of extinct species is not a new topic, in fact, it became popular in 1984 with examining dried quagga muscle tissue. Researchers then used this technique to confirm that the quagga, an extinct member of the horse family, really was as closely related to today’s horse as fossils suggested. Now researchers are looking at using Passenger Pigeon study skins to create a full genome of the species to better understand both its evolution and how to bring it back to today’s skies.

Be sure to check out the Tetrapod Collection’s campaign and help us purchase a new mobile cabinet for the extinct species in our collection. Our goal is to raise $5,500 and to educate people, about tetrapods throughout the month of October. Be sure to check out our videos, social media, blog and campaign page!

Passenger Pigeon profiles

Passenger Pigeons ©Hothem, 2016

 

About the Author: Stephanie Malinich is collection manager of the OSU tetrapods at the Museum of Biological Diversity.

 

Literature cited:

ELLSWORTH, J. W. and McCOMB, B. C. (2003), Potential Effects of Passenger Pigeon Flocks on the Structure and Composition of Presettlement Forests of Eastern North America. Conservation Biology, 17: 1548–1558. doi:10.1111/j.1523-1739.2003.00230.x

Impacts of Rain Gardens on Urban Bird Diversity

Rain gardens have proven to be a useful tool to mitigate stormwater run-off in cities. They are depressions on the side of the road or sidewalk with plants that absorb rainfall and prevent water from picking up pollutants and carrying them to the nearest stream. The plants and soil also filter the water. But this is not the only service rain gardens provide, the diversity of plants used in them increases habitat for many animals. Many insects and spiders are drawn to the local plants and they in return attract birds and small mammals. Rain gardens can provide nice shelter for these animals too.

As part of project “BluePrint” the City of Columbus plans to install some 500 rain gardens in the Clintonville area to manage stormwater runoff. Dr. Jay Martin, Professor of Ecological Engineering at OSU joined the project to holistically quantify the impacts of stormwater green infrastructure on societal services such as stormwater management, public health, community behavior, economics, and wildlife habitat. Dr. Martin’s PhD student David Wituszynski focuses on the animal aspect and recently contacted the Borror lab to discuss his research idea. David wants to test the hypothesis that implementation of such a large network of rain gardens will increase the diversity of urban bird species.

SongMeter mounted (https://www.wildlifeacoustics.com)

SongMeter mounted (https://www.wildlifeacoustics.com)

Specifically, he wants to develop automated acoustic methods to track urban bird populations. He will deploy SongMeters, automated recordings units, and program them to record surrounding sounds at certain times of the day. It is easy to record thousands of hours of bird and insect sound, but one needs to analyze them afterwards and identify vocalizing species.

This takes us back to the problem of automated sound recognition raised in Monday’s post. Dr. Martin and David are collaborating with Don Hayford from Columbus Innovation Group who will develop techniques to filter out background noise (such as human voices, machinery, cars, barking dogs – all familiar sounds to our neighborhoods) and produce files of target sounds that can then be analyzed with existing software.

My role will be to provide reference sounds for the software as we need to train the software to recognize known vocalizations of local bird species. This is not an easy task because some bird species have quite varied vocalizations. Our large and diverse archive of sound recordings will come in handy, we have many recordings of local Ohio species. These should cover most of their diverse vocalizations. Our goal is to build classifiers that automatically recognize and label species in the recordings.

map of Clintonville area with proposed rain gardens (project BluePrint, Columbus OH)

Will you get a rain garden on your street? check this map

We have just submitted a grant application to help us fund some of this research. The first SongMeters will be deployed this fall and we will start monitoring the areas to get a baseline level of bird activity. Come spring the city will install rain gardens in the neighborhood and we can compare our recordings before and after the installation. This certainly is a multi-year project. We will keep you updated.

Should you see a rain garden in your neighborhood, take a picture and share it on social media #BLB #raingarden #songmeter!

 

Further resources:

The project BluePrint was featured in the Columbus Dispatch last January!

Learn more about rain gardens in Central Ohio!

 

About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics at OSU and Co-PI on the project “Determining Impacts of Rain Gardens on Urban Bird Diversity” with Dr. Jay Martin, David Wituszynski and collaborator Don Hayford.

The holy grail of sound recognition: a birdsong recognition app

Listen to the cacophony of bird sounds at dawn. Does it make you want to be able to tell which species chime in? Wouldn’t it be nice to have an app “listen” with you and list all the bird species that are vocalizing? You are not alone, this is what researchers have been and are still working on. If you are somewhat familiar with bird song, you can imagine that it is not an easy task. Every species has its own characteristic sounds. But even within a species every individual most likely sings more than one rendition of the species-specific song and does so with variations.

Listen to the songs of the Yellow Warbler, Chestnut-sided Warbler and Yellow-throated Warbler, three species in the wood warbler family, that commonly sing in Ohio in spring.

Here is an example of two different song types sung by the same Yellow Warbler male:

Training software

To develop a bird song recognition app, software needs to be trained with real bird songs. An animal sound archive that houses thousands of recordings is an ideal resource for this endeavor. The Borror lab has provided many of our 47,000+ recordings to different researchers. Recently, Dr. Peter Jančovic, Senior Lecturer in the Department of Electronic, Electrical and Systems Engineering at the University of Birmingham, UK collaborated with us. He and his colleagues developed and tested an algorithm on over 33 hours of field recordings, containing 30 bird species (To put this in perspective, to-date 10,000 species of birds have been described and half of them are songbirds – so 30 species is really only the tip of the iceberg). But, his results are promising, the developed system recognizes bird species with an accuracy of 97.8% using 3 seconds of the detected signal. He presented these first results at the  International Conference on Acoustics, Speech and Signal Processing in Shanghai.

Sonogram of Yellow Warbler, not Yellow-throated Warbler song

The software correctly identified this sonogram as song from a Yellow Warbler.

Birdsong recognition apps

Some prototypes of birdsong recognition software and apps are already on the market.

bird song recognition apps: Warblr, Chirpomatic, Birdgenie

These are some of the already available bird song recognition apps that you may want to try.

 

Think of them as the Shazam of birdsong (For those of you not familiar with Shazam, it is an app that identifies music for you). Instead of sampling audio being played you record the bird’s song in question. The software will then compare features of the recorded sound against a database based on pre-recorded, identified sounds, a sound library.

 

Challenges and problems

This simple sounding process has challenges and problems: You need to get a really good recording of the bird you want to identify, i.e. no other birds singing nearby, no traffic noise, people talking or lawn mowers obscuring your target sound. Once you have managed this, a good app takes into account where in the world, even within the USA and within Ohio you recorded the song. Birds sing with local variations. Research in our lab has focused on this for many years: Birds learn their songs by imitating conspecific adults where they grow up and will incorporate any variations these birds sing in their repertoire. Thus the recorded sounds need to be compared to geographically correct songs of each species. Once the location has been set, the app needs to compare the recording to thousands of songs, because most of our songbirds sing at least 5 types of typical song, some sing over 100. Some like the Northern Mockingbird imitate the sounds of other species.

Geographic variation in song of Yellow Warbler YEWA

Listen to and compare Yellow Warbler songs from Ohio, Maine and Mexico, Baja California and Sonora.

I hope I have not completely discouraged you from trying one of the bird song recognition apps. They truly are an innovative application of the thousands of songs that have been recorded, archived and can be listened to for free. Have you already tried one of these apps? We would love to hear your experiences!

 

About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics.

 

Resources:

Jančovic, M. Köküer, M. Zakeri and M. Russell, “Bird species recognition using HMM-based unsupervised modelling of individual syllables with incorporated duration modelling,” 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Shanghai, 2016, pp. 559-563. doi: 10.1109/ICASSP.2016.7471737

Bird song ID apps

USA:
Bird Song Id USA Automatic Recognition and Reference – Songs and Calls of America
BirdGenie

UK:
Chirpomatic
Warblr

A comparison of Chirpomatic and Warblr for birds recorded in the UK.

Field ornithology

A recent post on Cool Green Science about Margaret Morse Nice “How a Scientific Outsider Changed How We Study Birds” inspired me to think more generally about how researchers study bird behavior in the field and how acoustic recordings can help us understand bird behavior. By the way, here “field” does not refer to a type of habitat rather it encompasses any natural habitat (rivers, lakes, meadows, forests etc.) in which animals live.

Margaret Morse Nice portrait

Margaret Morse Nice looking into a nest of baby sparrows, 1956 (Wikipedia)

Margaret Morse Nice’s most important contributions to ornithological research were probably in the advancement of techniques in studying birds. She was one of the few American women ornithologists in the 1930s and the first to make detailed observations of individual birds. She followed Song Sparrows through their lives, took notes on their life history and published her observations in over 200 papers and books. Most of her publications are listed in her autobiography “Research is a passion with me“.

cover of Margaret Morse Nice's book Research is a passion with me

Book by Margaret Morse Nice “Research is a passion with me”

Interestingly, Nice who was born in Massachusetts in 1883 studied Song Sparrows in Columbus, OH where she and her family lived in 1927-1936. During these eight years she closely followed birds on their property off Patterson Ave, a floodplain on the east-side of the Olentangy river just north of Lane Ave, what is today Tuttle park. Even though the habitat has changed from the shrubs, weeds and gardens in Nice’s time you can still find open areas especially along the river which Song Sparrows to this day use to build their nests and raise their young.

To follow individual birds closely, identify them repeatedly and note their behavior and interactions with each other, it was clear to Nice that she needed to mark the birds. Over the years she trapped some 870 Song Sparrows which she marked with unique combinations of plastic color bands on their legs. We still use the same technique today.

color-banded Song Sparrow

“Red-black / yellow-metal” banded Song Sparrow (c) K. Whittaker

Bird banding actually started in Europe as an aid to follow migrating birds and still is used for this purpose: Researchers put a metal band with an engraved unique number on a bird’s leg – just like your social security number. They report this number as well as where and when the bird was caught and banded to a central lab, here in the USA the central bird banding lab in Maryland. When somebody then recaptures or finds a banded bird, they can access this information through the bird banding lab and relate it to data they collect about the bird.

Colored leg bands help researchers to follow individual birds. Sounds easy? It can be once you have the colored leg bands on the bird. First you have to catch the bird and that can prove tricky. We primarily use two established bird trapping techniques: walk-in traps and mist-nets.

Just as the name implies, wire-mesh traps are placed on the ground, seeded with some tasty morsels and when the bird in search of food walks into the trap a door closes behind it and traps it within.

Collared Dove in a Potter Trap

Collared Dove in a Potter Trap (c) Third Wheel Ringing Supplies

For a mist-net imagine a volleyball net strapped between two poles but with finer mesh and all the way to the ground. These nets work best in foggy weather conditions when they are nearly invisible and when placed strategically in a bird’s flight path, the subject will fly into the mesh, bounce and fall into a fold at the bottom of the net and get entangled. We then “extract” the bird from the net and band it. – By the way not everybody can trap and band birds because they are highly protected under the Migratory Bird Treaty Act dating back to 1918. Through training with a master bird bander researchers can obtain a U. S. Federal Bird Banding and Marking Permit.

So what role does sound play in this? Sometimes we lure birds to the mist-net by playing calls or songs of its species. Why does this attract a bird? Most songbirds are territorial, i.e. they defend an area that they use exclusively for feeding or breeding and song keeps every other bird of the same species out of this territory. Some researchers have actually done clever experiments to prove this keep-out function of birdsong, but that is a story for another post.

Doug Nelson holding up a loudspeaker playing bird song in front of a mist net

Doug Nelson holding up a loudspeaker playing bird song in front of a mist-net in Oregon (c) Angelika Nelson

So, birds do not produce their most beautiful songs to please us, rather one function is to repel a male contender. If the opponent does not take this warning, a bird will switch to physical attack. Exactly this behavior can get them trapped in a mist-net as they search intently for the invisible opponent, aka loudspeaker, and eventually dive at in attack.

This brings me back to Nice’s contributions to field ornithology: Nice studied closely the territorial behavior of “her” birds. Once all males were banded she made close observations of where they sang, how they interacted with neighbors and whether they were able to attract a mate. She described patterns of invaders and defenders during territorial encounters and described the role that song played in these. To this day this is a prominent research topic in our lab where we have studied territorial singing behavior in the White-crowned Sparrow and other species over the last decades.

Following in the footsteps of Margaret Morse Nice, Dr. Chris Tonra, Assistant Professor in the School of Environmental and Natural Resources at Ohio State, has started a project to continue work on behavior of the Song Sparrow. He and his students regularly band today’s local Song Sparrow population at Ohio State’s Wilma H. Schiermeier Olentangy River Wetland Research Park, less than one km upstream from Nice’s former home, and follow them throughout the year. He uses some of the techniques from Nice’s days, others have advanced – read more about the project here!

 

About the author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics. Her recent research has focused on song and behavioral ecology of the White-crowned Sparrow in Oregon; each spring Angelika teaches the OSU course “Ohio Birds” where students learn about the life of birds and how to identify them in the field – by sight and sound.

 

References:

“Nice, Margaret Morse.” Complete Dictionary of Scientific Biography. 2008. Encyclopedia.com. (August 17, 2016).

Finding No-No

In our Muskingum River Survey we’re searching for a couple (invasive) fish species that we hope we do not find: The Silver and Bighead Carp.  Environmental DNA has been detected in the Muskingum River for Bighead Carp and also for Northern Snakehead, another invasive species from Asia.

This slideshow requires JavaScript.

 

 

And just as importantly, we’re taking names, numbers, weights and lengths of everything else we catch, documenting Muskingum River’s fish fauna before the Asian carp invade.  Just a few of the native species we’re catching or may catch soon that are found in the Muskingum:

 

This slideshow requires JavaScript.

 

About the Author: Marc Kibbey is Associate Curator of the Fish Division at the Museum of Biological Diversity.

Pre-Asian Carp Invasion: Muskingum River Survey

zano1_dsfrmybrdg

Photo of the Muskingum River from the National Weather Service

A little over two years ago a test of the Muskingum River using eDNA techniques showed positive results for Bighead Carp, one of several Asian carp species, and Northern Snakehead.  Although the Ohio Division of Natural Resources (ODNR) and U.S. Fish and Wildlife Service sampled the Muskingum River extensively neither of these invasive species was actually caught.  It may be that the highly sensitive eDNA technique picked up genetic material from bird feet or boat bottoms that traveled from areas where the invasive species were well established, but that has yet to be proven conclusively.

The OSUM Fish Division is currently carrying out a project to survey the Muskingum River watershed from top to bottom under the supervision of project leader Brian Zimmerman, with a grant from the Ohio DNR Division of Fish and Wildlife, overseen by Associate Professor and MBD director Meg Daly. Fifty-five sites above, below and in each of the nine pools between the locks and dams of the mainstem, and 5 each along the two major tributaries of the Muskingum River, Muskingum River lock and dam Photo from the Ohio Canal Society, the Walhonding and the Tuscarawas Rivers, will be sampled.

Muskingum River lock and dam, Photo from the Ohio Canal Society

Muskingum River lock and dam, Photo from the Ohio Canal Society

The sampling techniques will include

  1. Electroshocking: as the name implies, this technique involves the application of electrical current to stun fish, causing them to remain immobile for crew members with pole nets to retrieve them and place them in a large tub in the boat.
  2. Seining: The use of 6’ tall x 8’ wide seine nets by two or three people in this project to sample shallow areas.
  3. Benthic Trawling: We take an 18’ flat bottomed John boat with two 25 horsepower outboard motors and drag a small “otter” trawl net along the bottom of the river.
  4. Hoop Netting: This method uses 3 sets of large mesh nets supported by iron hoops. The hoop nets are left out for two days after which we return and remove the fish from the nets. Read more about this technique on our fish blog.

With all of the methods the catch is identified, counted, measured and weighed, and returned except for any invasive species we may catch (fortunately no Silver or Bighead Carp have been caught!…yet…). We see a very high rate of survival of the captured fish and these are returned to the river.

The project will extend over two years, from July to September of 2016 and 2017, and will culminate in a final report providing an assessment of the Muskingum River fish community.  This information will provide a baseline for use in potential remediation efforts should the silver and/or bighead carp become established above the Devola Dam.

Technically all carp (Silver, Bighead, Grass, Common, Black, and Prussian carp, and Goldfish are the species currently established in the United States but there are at least four more – Crucian, Catlan, Mrigal and Mud Carp- are recognized as valid species) are Asian in origin.  Common Carp, by the way, are believed to have originally come from the Caspian Sea.  Back in the 1880’s the U.S. Commission of Fish and Fisheries intentionally distributed Common Carp in rail cars across much of the United States to serve as a food fish, but the idea never caught on as extensively as hoped due to the habit of wild carp to scavenge the bottom of water bodies.

Common Carp are invasive, but are considered naturalized.  They can be deleterious to stream and lake bottoms, and do impact other fish, bird, and mollusk species as well as plants, but at this point the damage has been done, so to speak.  After nearly 140 years native fish and other animals have adapted to Common Carp.  Some fishermen and environmental agents prefer to kill Common Carp whenever they are caught, in many cases simply throwing them on the stream bank to suffocate, but in truth this has little if any effect on the population since their recruitment rate is extremely high.

Silver and Bighead Carp were brought to the United States during the 1970’s and 1980’s, and escaped into the Mississippi River watershed from their state, federal and privately run facilities following extensive rains that overflowed the hatcheries.  In the Mississippi River and many tributaries they are securely established in abundances that impact native fish species and interfere with local trawling concerns.

Adult fish species that are known to be adversely affected by Silver and Bighead Carp are Gizzard Shad and Bigmouth Buffalo.  The dietary overlap of the carp with these native fishes has been shown to reduce the adults’ size and health.  In addition the high volume planktonic grazing employed by these carp is likely to compete for that food source with larvae and young-of-the-year of most other native fishes, ultimately causing a reduction in native populations.

Grass Carp are established in lakes and rivers across the State of Ohio.  Deleterious effects from this invader include removal of macrophytes (large aquatic plants) from stream bottoms with concurrent increases in turbidity.  The macrophytes provide cover and spawning habitat for many native organisms.  The carp only digest about 1/2 of the plants they eat, so the large amounts of fecal matter cause algal blooms.  The OSUM crew has caught several Grass Carp already, euthanizing and saving samples from them.

It is not known at this point what the remediation would consist of if Bighead or Silver Carp do invade the Muskingum River.  Similar to many other invasive species it would be extremely difficult if not impossible to completely eradicate them from waterways like the Muskingum River that have connections to other rivers that contain the species.  Short of completely damming the river (which carries its own set of ecological problems), or installing an electric barrier as has been done between the Illinois River and Lake Michigan, eradication would be short-lived.  It may be that the best approach would be to simply utilize the pests as a food source as has been done in Kentucky and other states, since their flesh is much more palatable than that of common carp.  If we catch any Bighead or Silver Carp (electroshocking works well for larger Silver Carp, while hoop netting is one of the best methods for Bigheads) they will be euthanized with samples taken for DNA analysis, but we really do hope that is not the case.

 

About the Author: Marc Kibbey is Associate Curator of the Fish Division at the Museum of Biological Diversity.

Mites and moths

Following some earlier blogs about recently acquired collections I present to you here the Treat collection. This collection was assembled by Asher E. Treat a researcher at City University of New York and the American Museum of Natural History, also New York. This collection is one of the best in the world for mites associated with Lepidoptera (butterflies and moths). Mites have been found associated with most terrestrial and many aquatic organisms, but when it comes to insect hosts, mites on Coleoptera (beetles) and Hymenoptera (bees and wasps) are clearly the most numerous, diverse, and well-known. Still, Lepidoptera have a variety of associated mites.

The Acarology Collection acquired this collection 4 years ago, some years after Treat’s death. The collection consisted of about 37 slide boxes of exceptionally well labelled microscope slides and half a dozen insect drawers of pinned moths (all labelled as hosts of specific mite specimens). The Lepidoptera are being processed at the Triplehorn Insect collection, while we, the Acarology collection, have been working on processing (mostly databasing) the slides. This is proving to be a major job.

 

Image of a female of Dicrocheles phalaenodectes, the moth ear mite

Image of a female of Dicrocheles phalaenodectes, the moth ear mite

Treat got interested in mites associated with moths after finding mites in the ears of noctuid moths. In the process, he figured out the quite amazing life histories of some mites associated with these moths. The most famous is Dicrocheles phalaenodectes, the moth ear mite (family Laelapidae).

These mites break through the tympanic membrane of the ear of the moth and form small colonies inside the ear. By itself not too surprising, but the interesting part Treat discovered was that these mites are always found in one ear only, rarely if ever in both ears. In a way this makes sense. By breaking the tympanic membrane the mites make the moth deaf in that ear. Moths need their hearing to avoid predators (for example bats) so a deaf moth would be easy prey. However, a moth with one functional ear is still able to avoid bats, perhaps not as well as if it had two functional ears, but close enough. Which leaves the question: how do the mites manage to limit infestations to one ear?

Treat did many careful observations and follow-up experiments on this aspect and found that the mites have a very specific set of behaviors ensuring only one ear will be parasitized. The first female to get on a moth (nearly always a fertilized female, the immatures and males do not colonize) crawls to the dorsal part of the thorax, explores a little, after which she proceeds to one ear. Any future colonizers will first go to that same dorsal part of the thorax of the moth and follow the initial female to the same ear. It appears the mites lay a pheromone trail that guides newcomers to the already infested ear, and away from the uninfested one.

Drawing of relative positions of mites in a moth ear

Drawing of relative positions of mites in a moth ear

To complete the cycle, young females leaving the ear initially wander around the hosts body (mostly the thorax), congregating around the head at night. They leave the moth by running down its proboscis when it is feeding on flowers. On the flowers, the mites wait for their next host.
Another mite family that is specialized on Lepidoptera, the Otopheidomenidae, is also parasitic, and they will also show up near the ears, but they do not pierce the tympanic membrane, so they do not cause deafness. Unfortunately, we know much less about them, Treat was never able to study their behavior. A range of other mite families have representatives that are regularly found on Lepidoptera, but they are not specialists at the family level: Ameroseiidae, Melicharidae, Erythraeidae, Iolinidae, Cheyletidae, Acaridae, Carpoglyphidae, and Histiostomatidae. That list excludes the occasional “vagrants” that can be found on moths, but that are unlikely to be living on them for extended periods of time. All in all, quite a diverse community.
For those interested in knowing more, Treat wrote a book “Mites of Moths and Butterflies” (1975, Cornell University Press) that is a rare combination of good scholarship (especially natural history) and readability.

Title page of Treat's book on moth mites

Title page of Treat’s book on moth mites

Treat was very careful and noted things like host specimen numbers (if available), which allows current researchers to track down the exact moth from which a given mite came.

This is currently a common approach, but Treat started this in the 1950-ies. And there is more. Based on Treat’s label data we know not only the name of the hosts and the specific locality, but also gender of the host, whether the left or right ear was infested, and the exact part of the body the mites were found on. So we have excellent information, directly from the slides, showing that Proctolaelaps species (family Melicharidae) are nearly always found near the base of the palps [as an aside, Proctolaelaps is a bit of an unfortunate generic name, combining “procto-” = anus and “laelaps” = hurricane; presumably the name

Microscope slide from the Treat collection

Slide from the Treat collection

refers to a relatively large anal shield]. Such complete data are fantastic for future research, but they also mean a lot more work processing these slides, as every slide has lots of unique data. I want to thank George Keeney, part-time curator of the acarology collection and a series of volunteers, Ben Carey, Rachel Hitt, Mitchell Maynard, Ben Mooney, Jake Waltermyer, and Elijah Williams, for their hard work in accessioning this material.

 

About the Author: Dr. Hans Klompen is professor in the department of Evolution, Ecology and Organismal Biology and director of the Ohio State University Acarology Collection.