Research

Evolution of hyperiid amphipod visual systems

The amazing eyes of hyperiid amphipods defy reason. With everything from no eyes though, simple pigment cups, cylindrical eyes with a 360 degree field of view, eyes with crystalline cones that function like fiber optics, extra pairs of eyes, eyes that take up their entire head and up to nearly half the body, and blinders made of exoskeleton, this suborder of crustaceans are an amazing group to study how midwater animals have adapted to the unique challenges of life in the largest habitat on earth. In this project we are using an integrative approach that combines studies of visual physiology, behavior, phylogenetic history, transcriptomics, neurobiology, and oceanography to ask questions like what can individual species see, how do their visual capabilities relate to their habits (depth, associations with gelatinous zooplankton, migration, free-swimming or symbiotic), and how have their visual traits evolved over time. Primary collaborators include Jan Hemmi (University of Western Australia), Tom Cronin (University of Maryland, Baltimore County), Bill Browne (University of Miami), Annie Jessop (University of Western Australia), Jessica Goodheart (University of California, Santa Barbara), Sonke Johnsen (Duke University). Past contributors include Jamie Baldwin Fergus, Laura Bagge and Leann Biancani. Publications include: Baldwin et al. 2015, Bagge et al. 2016, Biancani 2019 (https://drum.lib.umd.edu/handle/1903/24888).

Tomopterid worm biology

Tomopterid polychaetes are some of the most beautiful animals in the midwater. They range in size from a few millimeters to nearly a meter in length. Approximately 70 species have been described of these active predators, which are found throughout the entire depth of the midwater. Little is known about their biology and they are difficult to identify, especially when alive. By collecting them, photographing key characteristics and taking tissue samples for genetic work, we are sorting out the different species and their distributions, generating characters that will allow identification of them when alive, and building a phylogenetic reconstruction of their evolutionary history in order to study evolution of their unique yellow bioluminescence, and working on a taxonomic revision for the family (a very long-term project). We are also studying the kinematics of their swimming, in other words, how they accomplish their stealthy, quick movements through the water. My primary collaborators on the project are Kakani Katija (MBARI), Joost Daniels (MBARI), and Sarit Truskey (Northeastern University). Publications include: Bentlage et al. 2018.

Blackfish

In deep-sea fishes, black surfaces strongly absorb (and thus do not reflect) the bioluminescent searchlights of predators and ambient bioluminescence abundant in the deep sea, therefore providing a form of camouflage. Many deep-sea fishes are exceptionally black – this is most obvious when trying to photograph them and ending up with a series of silhouettes.  For years it has been assumed that black fish were simply highly pigmented, but we asked if there is more to it than this.  We used histological techniques with light, scanning, transmission electron microscopy, and optical modeling to document the skin and pigmentation of these fishes. This study highlights unique, convergent adaptations of deep-sea fishes and expands our knowledge of the structure of fish skin.  My collaborators on this project are Sonke Johnsen and Katie Thomas (Duke University). 

Scaleworm evolution

Scaleworms are arguably the most successful, certainly the most diverse and widespread, group of marine segmented worms.  They are observed regularly in the midwater although they aren’t known to occur there normally except for a few oddball species.  With the arrival of Brett Gonzalez, we stated to explore questions of their adaptations to life in the water column.  We started examining adaptations to swim and drift and are working on resolving relationships within the group, describing key new species (as with so many invertebrate groups there are so many that need description, we can’t possibly do them all), and have also become interested in the diversity of eyes found across the group.  Primary collaborators on the project are Katrine Worsaae and Marc Allentoft (University of Copenhagen).

Deep-sea acorn worm biology

The Torquaratoridae are a group of deep-sea acorn worms first described in 2005 and since, observed all over the deep-sea floor. They are abundant, morphologically diverse, as acorn worms go, large, often colorful, and instead of living in burrows in sediment, they live out of the surface of the deep-sea floor or drifting above it. They are found on soft sediment to fresh lava flows. We are working to describe the major clades within the Torquaratoridae, their unusual reproductive biology, their behavior, and their evolutionary history. Primary collaborators include Nick Holland (University of California, San Diego), Linda Kuhnz (MBARI), and Ken Smith (MBARI). Publications include: Osborn et al. 2012, Holland et al. 2012a & b, Priede et al. 2012, Holland et al. 2013, Osborn et al. 2013. At this time, there is much work to be done on this subject with material in hand but no one actively working on this project so if you are interested in joining the project, contact me.

Cirratuliform worm diversity

Several large swimming worms, which were all more closely related to each other than any other known worms, were discovered in deep-water over the past 15 years. Several have been described including Swima bombiviridis (the green bomber), Swima fulgida (the shining bomber), Swima tawitawiensis (the orange bomber), and Teuthidodrilus samae (squidworm) but many remain to be described and named. This group is particularly interesting because it contains a range of species, some are completely benthic, others are completely pelagic, and still others spend part of their time on the seafloor and part in the water column. Because of this range of lifestyles, they are an excellent group to study adaptations to and changes in morphology and behavior when transitioning from benthic to pelagic lifestyle. They are also large, abundant animals that likely have a large impact on the communities they are a part of and are thus ecologically important animals. Publications include: Osborn & Rouse 2008, 2010, Osborn et al. 2009, 2010, 2011. At this time, there is much work to be done on this subject with material in hand but no one actively working on this project, so if you are interested in joining the project, contact me.

Munnopsid isopod natural history

The unusual crustacean family Munnopsidae contains the majority of free-living, pelagic isopods. They are extremely abundant in the deep-sea and nearly exclusive to this habitat. In contrast to the typical uniform body of isopods, munnopsids have specialized legs and body segments. Three of these specialized pairs of legs are used to swim backward through the water and two to three other pairs are extremely elongate and used for parachuting, striding and particle collecting. The movements of these animals, particularly their swimming and elongate legs are a fascinating example of automated and largely passive movement. We are interested in many aspects of their biology including their feeding habits, describing the many undescribed species, and their diversification patterns. Primary collaborators include: Sarah Schnurr and Saskia Brix (Senkenberg DZMB) and Sarit Truskey (Northeastern University). Publications include: Osborn 2009, Schnurr et al. 2018, Brix et al. 2019. At this time, there is much work to be done on this subject with material in hand but no one focusing on this project, so if you are interested in joining the project, contact me.

StreamCode

This was a proof of concept project with Michael Boyle (Smithsonian Marine Station), Paula Pappalardo, Katrina Lohan (Smithsonian Environmental Research Center), Allen Collins (NOAA/NMNFS), Kate Hansen (Duke University), Sarit Truskey (Northeastern University) and the StreamCode Team that was funded by SI-NMNH Science, the Global Genome Initiative, and Smithsonian Barcode Consortium.  We documented the genetic, life history, and systematic

The lab participates in research expeditions with:

• Monterey Bay Aquarium Research Institute off of the west coast of North America
• Samples the Gulf Stream from the Smithsonian Marine Station, Fort Pierce, Florida
• Collaborates with Dr. Henk Jan Hoving (GEOMAR) using the submersible Jago