April 27, 2024

Stunning Diversity of Comb Jellies Revealed Through Genetic Probes

This work– funded by the David and Lucile Packard Foundation, the National Science Foundation, and the National Institutes of Health– unlocks for future research study on comb jellies utilizing eDNA, or ecological DNA. eDNA holds pledge for detecting marine animals from the wandering little bits of genetic material they leave in seawater. “Importantly, the hereditary information we have shared to public databases will provide a valuable referral for others using eDNA to assist reveal the complexity of ocean ecosystems,” stated Christianson.
Scientists have explained around 200 comb jelly species so far. They can be found in a selection of shapes, patterns, colors, and sizes. Some are little, while others like this giant comb jelly (Aulacoctena sp.) can be rather big– growing larger than a football. All play an essential role in ocean communities. Credit: © 2006 MBARI
Comb jellies live throughout the ocean, from the shallow depths to the deep seafloor and from warm tropical seas to cold polar waters. Although they are a fundamental part of marine environments, the obstacle of collecting undamaged specimens, especially from the deep sea, makes them hard to study. “Most scientists are unable to collect comb jellies in any recognizable manner– they are simply too fragile,” described MBARI Senior Scientist Steve Haddock.
Blue-water diving is among several methods utilized by MBARI scientists to gather fragile ctenophores. Credit: Steve Haddock © 2018 MBARI.
But MBARI is uniquely equipped to study these delicate drifters.
MBARIs research vessels use a platform for blue-water diving– a form of diving far offshore suspended in open water– and deployment of specialized robotic submersibles called remotely run cars (ROVs).
MBARI scientists prepared a “tree” of relationships utilizing COI series to reveal types differences in between comb jellies. Major branches consist of the lobed comb jellies (pink), beroids (blue), and the seafloor-dwelling platyctenes (green).
Utilizing both scuba and submersibles, MBARI scientists have actually been able to thoroughly gather comb jellies for research study in the lab. For years, they have actually accumulated a collection of specimens representing nearly every understood household of comb jellies.
Studying these animals from their appearance alone has been important, however has at times been an imperfect science. Some specimens are damaged, some distinguishing qualities between species are cryptic, and some tissues are too delicate for conservation. In addition to examining the look of live animals, MBARI scientists have turned to genes to identify and brochure their specimens.
Previous research study questioned if the train track comb jelly (Deiopea kaloktenota, visualized) may be a juvenile kind of the rabbit-eared comb jelly (Kiyohimea usagi, next). Hereditary analysis has now validated the two are indeed special– and raised the possibility that there are really 2 types of Deiopea off main California. Credit: © 2020 MBARI
The mitochondrial gene cytochrome-c-oxidase subunit I (COI) resembles a genetic finger print for animals. This gene is extensively used in whatever from bees to baboons for identifying types and even geographic subpopulations. Constructing a library of ctenophore “fingerprints,” though, was no simple task.
Previous research questioned if the train track comb jelly (Deiopea kaloktenota, previous) might be a juvenile kind of the rabbit-eared comb jelly (Kiyohimea usagi, pictured). Genetic analysis has now confirmed the two are undoubtedly special– and raised the possibility that there are really two types of Deiopea off central California. Credit: © 2019 MBARI
To read these genes, researchers use primers– brief, manufactured DNA pieces that complement sections of DNA discovered in a species genome and serve as anchor points to begin genetic sequencing. The DNA of comb jellies is so different from other animals that the basic guides do not work for a lot of comb jelly types. The team set out to resolve this issue. The team had to make primers that would work on comb jelly COI sequences. They did this by examining the genomes of comb jellies and screening hundreds of guide combinations. They used those guides to produce the library of specific series from across hundreds of comb jelly specimens they had actually gathered. These are the 2 most impactful outcomes of the work.
Comparing COI gene sequences revealed 2 branches of the family tree for the lobed comb jelly genus Bolinopsis. One branch consisted of four tropical types and the associated warty comb jelly (Mnemiopsis leidyi), while another consisted of two species from cooler temperate waters. Credit: © 2006 MBARI
The group produced the most total library of DNA series from comb jellies, adding 72 types to the international database where only 15 had actually been represented before. By comparing series of the COI gene, they likewise developed a more precise family tree for comb jellies at the species level.
This brand-new library of hereditary information assisted clarify relationships in between similar-looking types. The genetic probes have sparked a number of brand-new questions about common species.
Studying the COI gene has actually shed brand-new light on the identities of scallop comb jellies in the genus Bathocyroe seen off the coast of California. Hereditary analysis has actually recommended three unique– and potentially formerly unidentified– types may take place off the Central Coast. Credit: © 2003 MBARI
A more detailed look at its COI gene recommended three distinct species live off our coast. None seem to align with the 3 recognized species in the genus. Small differences in appearance and depth circulation from the acknowledged types of Bathocyroe recommend the three types off Californias Central Coast might be brand-new to science.
The bloody-belly comb jelly (Lampocteis cruentiventer, visualized) is one of the most sensational comb jellies in the depths of Monterey Bay. In some cases MBARIs ROVs experience an amber-colored variation and a deep-dwelling purple-colored variant. Brand-new genetic analysis has verified researchers suspicions that these two are not unusual color morphs of the crimson ctenophore, but in fact unique types. Credit: © 2006 MBARI
In 34 years of research study, MBARI has recorded more than 200 types formerly unidentified to researchers. One such discover was the bloody-belly comb jelly (Lampocteis cruentiventer). MBARI scientists George Matsumoto and Bruce Robison contributed to the original description of this types in 2001.
The bloody-belly comb jelly (Lampocteis cruentiventer) is among the most spectacular comb jellies in the depths of Monterey Bay. Often MBARIs ROVs encounter an amber-colored version (visualized) and a deep-dwelling purple-colored variant (next). Brand-new hereditary analysis has verified researchers suspicions that these 2 are not odd color morphs of the crimson ctenophore, however in truth distinct species. Credit: © 2004 MBARI
There are presently 200 known, or explained, comb jelly species. With the COI gene sequences hinting that some of these might be more than one genetically distinct types, that count is likely to grow 3- or even fourfold.
” Everywhere that we have actually been able to look in information has exposed hidden variety, suggesting there are a lot more species of ctenophores than our most optimistic quotes,” stated Haddock.
Taking a look at comb jellies collected from more locations around the world will be a vital next step for understanding relationships among these animals by comparing the sequences of possibly undescribed types to sequences from species officially recognized by scientists. The COI gene supplies a helpful starting point for researchers to focus their work.
The bloody-belly comb jelly (Lampocteis cruentiventer) is one of the most sensational comb jellies in the depths of Monterey Bay. Often MBARIs ROVs encounter an amber-colored variation (previous) and a deep-dwelling purple-colored version (envisioned). New genetic analysis has confirmed researchers suspicions that these two are not strange color morphs of the crimson ctenophore, but in reality distinct species. Credit: © 2002 MBARI
This work has actually laid the structure for researchers around the globe to check out the hereditary finger prints of comb jellies left behind in eDNA and improve efforts to catalog the diversity of life in the ocean. Comb jellies have mainly been left out from the appealing new field of fast types identifications since of the deficiency of COI gene series for this group essential to find the eDNA they leave behind.
The MBARI research study team has actually now offered tools for other researchers to begin fast recognitions of comb jellies. Samples from MBARI and our collaborators have added five times as many comb jelly types to the National Center for Biotechnology Information archives as have actually been previously sequenced. “We are supplying hereditary series for an unmatched number of ctenophore types into public databases for all to use,” said Christianson.
Who understands what brand-new discoveries wait for now?
Reference: “Hidden variety of Ctenophora revealed by new mitochondrial COI guides and series” by Lynne M. Christianson, Shannon B. Johnson, Darrin T. Schultz and Steven H. D. Haddock, 5 July 2022, Molecular Ecology Resources.DOI: 10.1111/ 1755-0998.13459.

Researchers from the Monterey Bay Aquarium Research Institute (MBARI) have utilized genes to study the comb jellies, or ctenophores, and have actually discovered new variety within the species.
Comb jellies– known to researchers as ctenophores (pronounced “teen-oh-fours”)– enthrall with their appeal, however these fascinating creatures stay badly studied due to their delicate nature. MBARI scientists have actually utilized the power of genetics to discover more about these animals.
In a research study released in the journal Molecular Ecology Resources, MBARI scientists Lynne Christianson, Shannon Johnson, Darrin Schultz, and Steve Haddock analyzed a specific gene sequence in comb jellies. This series has exposed untold diversity within this group of animals.
” Using genetics, we found surprising variety in some groups, including some more commonly-seen species that were formerly considered a single types, however are now revealed to be numerous types,” said Lynne Christianson, lead author on the study and a senior research study service technician at MBARI This research also uncovered numerous comb jelly species that are brand-new to science.

Previous research study questioned if the train track comb jelly (Deiopea kaloktenota, pictured) may be a juvenile type of the rabbit-eared comb jelly (Kiyohimea usagi, next). Previous research study questioned if the train track comb jelly (Deiopea kaloktenota, previous) may be a juvenile form of the rabbit-eared comb jelly (Kiyohimea usagi, envisioned). The DNA of comb jellies is so various from other animals that the standard primers do not work for the majority of comb jelly species. The bloody-belly comb jelly (Lampocteis cruentiventer, imagined) is one of the most sensational comb jellies in the depths of Monterey Bay. The bloody-belly comb jelly (Lampocteis cruentiventer) is one of the most sensational comb jellies in the depths of Monterey Bay.