Dr. Nancy Sheridan
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nsheridan.bsky.social
Dr. Nancy Sheridan
@nsheridan.bsky.social
Geneticist in Florida focusing on🪸🐠🦀🦐🐚 and other marine organisms.
🌊✨ Here’s a look at Montastraea cavernosa, the great star coral—found from reefs to the deep. 🪸🦑 #stonycoralSunday
February 24, 2025 at 3:42 AM
🌊 Masters of disguise. 🐡 Fowlerichthys ocellatus blends seamlessly with tunicates, using incredible camouflage to ambush prey. This adaptation may be shaped by local selective pressures, potentially driving 🧬 genetic variation across populations. 🪸🦑🌎 #tunicateTuesday
📸 @hthoricht.bsky.social
February 11, 2025 at 10:08 PM
The world: 🔥🔥🔥

Me: do u wanna see a coral reef
February 6, 2025 at 1:00 AM
✨The giant Caribbean sea anemone Condylactis gigantea shelters cleaner shrimp, crabs, and fish that seek protection in its stinging tentacles. 🧬 Genetically, it’s well-mixed across South Florida, with weak differentiation. #tentacleTuesday 🪸🦑🌎
📸 Heidi Thoricht
February 4, 2025 at 11:27 PM
🌊🐟 A belted sandfish (Serranus subligarius) with a horse conch (Triplofusus giganteus), one of the largest, most voracious predatory gastropods in the world. Sandfish show high gene flow in the Gulf & Atlantic, but such 🧬 data are lacking for the horse conch. 🪸🦑🌎 #MolluscMonday
📸: Heidi Thoricht
February 4, 2025 at 1:16 AM
🐠Yellowhead jawfish (Opistognathus aurifrons) are expert burrow builders, 🧬adapting perfectly to sandy reef habitats. Males take family care to the next level, mouthbrooding eggs until they hatch. Their sedentary lifestyle leads to localized populations with unique traits. 🪸🌊🦑🌎
📸: Mike Miller
January 26, 2025 at 11:43 PM
🪸Dichocoenia stokesii (aka elliptical star ⭐ or pineapple🍍coral) in the western Atlantic and Caribbean 🌊 is prone to diseases and bleaching. 🧬Genetic studies can help conservation efforts and improve resilience (e.g., identify disease-resistant genotypes for breeding or rescue). #stonycoralSunday 🦑🌎
January 19, 2025 at 9:01 PM
✨🌊 Did you know sea spiders (pycnogonids) lack key Hox genes 🧬 like abdominal-A, crucial for body segmentation? This genetic quirk gives them their unique, leg-dominated body plan. Ancient, mysterious, and oddly beautiful—check out this striking photo of one! 🧪🌎🦑🪸#SeaSpiderSaturday
📸: Mike Miller
January 18, 2025 at 5:34 PM
🌊 Meet Cinachyrella alloclada! This orange ball sponge, seen here with budding mini-clones alongside red algae, tube worms, and coral, reproduces sexually (free-swimming larvae) and asexually (budding). Its 🧬 genetics power bioactive compounds that deter predators and rivals. 💛🪸🦑
📸: Heidi Thoricht
January 10, 2025 at 1:09 AM
🪸 The spiny flower coral (Mussa angulosa) occurs either solo or in colonies of large, fleshy polyps in the Caribbean and Gulf of Mexico. Its common name stems from the sharp spiked plates (septa) of its skeleton. 🧬Genetic studies are lacking. 🦑
January 3, 2025 at 11:52 PM
✨Happy New Year! Here’s a video 🎥 of an Octopus spp. my dive buddy, Ali, found during our 🪸 surveys. Hope we all have fun discoveries in 2025! 🌊🦑
January 1, 2025 at 6:18 PM
🪸Ending the year with a banded eye hermit crab (Paguristes tortugae). 🦀 These crabs are native to the 🌊 Caribbean and Gulf of Mexico, are a species complex, 🧬 and belong to the family Diogenidae, known as the "left-handed hermit crabs" because their left claw is larger than the right. 🌎🦑
December 31, 2024 at 11:52 PM
🪸Gracilaria – a type of red algae that the spotted sea hare eats – thrives under stress. With heat shock proteins, salt tolerance genes, and agar-producing pathways, it’s a biotech treasure for sustainable agar, biofuels, and even pharmaceuticals. #SeaScience 🌊🧬🦑
December 30, 2024 at 11:41 PM
🌊A spotted sea hare (Aplysia dactylomela) moving along the sea floor. 🪸When threatened, they release purple ink to confuse predators. Their algal diet shapes their color and defenses, with studies suggesting they may acquire genes or metabolites from the algae. #molluscMonday 🧬🦑🌎
📸: Heidi Thoricht
December 30, 2024 at 11:40 PM
✨Happy holidays to all! 🎄Christmas tree worms (Spirobranchus giganteus) in mustard hill coral (Porites astreoides). This coral shows notable genetic diversity and connectivity across its range, but such info for the worm species is sparse. #wormWednesday #reefmas 🪱🧬🦑🌎 🪸
December 25, 2024 at 11:07 PM
🪸Fun find! A banded clinging crab (Mithraculus cinctimanus) among Florida false coral (Ricordea florida). The 🦀 is a scavenger and algae grazer with scarce genetic info. R. florida shows complex connectivity, with 2 distinct lineages sharing overlapping geographic ranges. #crustmas #reefmas 🦑🌎
December 25, 2024 at 1:26 AM
🌊 A vibrant Fasciolaria tulipa! 🐚✨The tulip snail’s sturdy, spiraled shell is crafted at the molecular level through biomineralization genes. 🧬 It’s a predatory snail that feeds on bivalves by using its specialized radula to drill holes in their shells. #molluscMonday #reefmas 🪸🦑
📸: Heidi Thoricht
December 24, 2024 at 2:51 AM
Schooling porkfish (Anisotremus virginicus) 🐠🪸🦑
📸: Doug Perrine
December 21, 2024 at 1:11 AM
🐠 A porkfish (Anisotremus virginicus) cruising through an octocoral garden. 🪸 An indicator of healthy reefs due to their sensitivity to environmental changes. Its populations show strong genetic structure, with limited gene flow shaped by ocean currents. #octocoralFriday #fishmas #reefmas 🧬🦑🌎
December 21, 2024 at 1:09 AM
✨Festive sea frost for #wormWednesday! 🪱 Salmacina huxleyi builds its own home by secreting calcareous tubes, adding to the seafloor’s complexity.🪸 Little is known about their genetics. 🧬 The ocean still holds so many mysteries! #reefmas 🌊🦑🌎
📸: Heidi Thoricht
December 19, 2024 at 1:33 AM
🌊Check out these two! 🦀 Paguristes puncticeps, the white-speckled hermit crab, shares space with (possibly) Pomatostegus stellatus, a star-like serpulid worm (top left). Though genetic studies are lacking, related hermit crabs show both high connectivity and cryptic diversity. #crustmas #reefmas🧬🪸🦑🌎
December 17, 2024 at 12:37 AM
🐟 A butter hamlet with octocorals! 🪸 As simultaneous hermaphrodites, they spawn in pairs, with mates strongly assorting by color pattern—even when multiple hamlets share the same area. Gulf hamlets are distinct, while Caribbean hamlets are genetically alike.🧬 #fishmas #reefmas #octocoralFriday 🦑🌎
December 14, 2024 at 12:12 AM
🪸The lightbulb anemone Bellactis lux known from the Gulf of Mexico since the 1990s was described by @anemone-padawan.bsky.social, Paul Larson, yours truly, & @megdaly.bsky.social, and named after its tentacle tips resembling a 💡 Genomic 🧬 insights on this anemone are forthcoming.
December 11, 2024 at 1:06 AM
✨A stunning photo of the giant tunicate Polycarpa spongiabilis (right and center) and the lightbulb anemone Bellactis lux (center and left) from the Gulf of Mexico. Genetic 🧬 studies on this tunicate are lacking 🌊 #tunicateTuesday 🪸🦑
📸: Mike Miller
December 11, 2024 at 12:59 AM
🌊🤿 Our bubble watcher several years ago—the brown noddy Anous stolidus nests in huge colonies at Dry Tortugas, an essential breeding ground. SW Atlantic populations are genetically 🧬 similar but vary in size and diet across colonies, revealing ecological plasticity. 🪸🌎🦑 #Seabirds
December 8, 2024 at 11:55 PM