#that one parasite that force-femmes crabs

[bethanythebogwitch]

Y'all voted for a crustacean for Wet Beast Wednesday so I picked possibly the weirdest one to go over. We're talking about barnacles. Barnacles were initially classified as mollusks for understandable reasons as they look a lot like limpets. It wasn't until observation of the larvae that they were reclassified as very strange crustaceans. The hard outer shell contains a little crabby critter that will spend its entire life within. Barnacles can be loosely divided into acorn barnacles, who have their shells directly attached to a solid surface, and goose barnacles, who use a thick, muscular stalk they use to attach.

(image: acorn barnacles)

(image: goose barnacles)

Barnacle shells are derived from the same structures as the carapace of other crustaceans, leaving the barnacle within as a fleshy blob. Most species have an operculum that can open to allow feeding or close to retain water and avoid predators. The vast majority of barnacles are suspension feeders who will stick their legs out of the shell. These legs are covered in sticky filaments that snag plankton and organic material that will be pulled down to the mouth. A few goose barnacles lack cirri and require water movement to bring food into their shells. Barnacles that live in intertidal zones (roughly 25% of species) will close their shells during low tide to retain water. Because barnacles are so sedentary, they lack hearts and gills.

(image: a diagram of barnacle anatomy)

Most barnacles are simultaneous hermaphrodites, producing male and female gametes at the same time (as opposed to sequential hermaphrodites, who change sex during their lives), those some species are gonochoric (distinct males and females) or androdioecious (distinct males and hermaphrodites). Because they are sessile, mating is difficult for barnacles and they have developed internal and external reproduction depending on species. Those that reproduce internally have enormously long, flexible penises that are used to reach and fertilize their neighbors. The barnacle famously has the longest penis to body size ration of any animal, with the penis growing up to 8 times longer than the rest of the animal. Other species use a technique called spermcasting in which male gametes are released into the water and picked up by females/hermaphrodites for fertilization. Juvenile barnacles go through two distinct larval stages. The first of these is the nauplius, a one-eyed, free-swimming larva that will go through 6 molts before transforming into the next stage. The next stage is the cyprid and its only purpose it to find a suitable pace to spend the rest of its life. It will use its antennae to examine hard surfaces with a number of criteria including surface texture, chemistry, color, biofilm, and the presence of other barnacles. Cyprids have limited energy stores as they cannot feed and test have shown they get less picky the longer they spend in this stage. Once a cyprid finds a suitable spot it will permanently attach itself headfirst using a secreted glue and metamorphose into a juvenile barnacle.

(image: a diagram of barnacle life stages)

Some species of barnacle aren't content living on rocks and instead attach to animals. Various barnacle species have adapted to latch onto other animals, including whales, sea turtles, mollusks, crustaceans, and other arthropods. In most cases, these barnacles have a commensal relationship with their hosts; the barnacle gets the benefit of a free ride and protection from predators while the host neither benefits or suffers from the relationship. In cases of heavy infestation, the barnacles could cause irritation or drag and could cause problems for their hosts. One group of barnacles, the rhizocephalans, have gone further and adapted a fully parasitic lifestyle. These have become so heavily adapted they are virtually unrecognizable as barnacles or even arthropods, lacking shells, appendages, body segments, and most organs. A female consists of gonads, a few muscles, the remnants of a nervous system, and a cuticle. Males have even less, they are reduced to a cluster of cells that live inside the females to provide a constant supply of sperm. Parasitic barnacles mostly target decapods (crabs, lobsters, shrimp, etc) thous some species target other crustaceans, including other barnacles. When a female larva attaches to a host, it grows a root-like cell mass called the vermigon into the host's body that absorbs nutrients through the host's blood. The most famous group of parasitic barnacles are in the genus Sacculina, who parasitize crabs. When these barnacles attach to a crab, they sterilize it and prevent it from molting or regrowing lost limbs. It also grows a sac where the female crab would hold its egg sac and forces the crab to protect it as if it really were an egg sac. When Sacculina infests a male crab, it interferes with hormones, causing the male crab to take on a feminine body plan and act female. When the barnacle is ready to release its larvae, the crab will assist as though it was releasing its own egg case.

(Image: Sacculina force-femming a crab)

Goose barnacles are the subject of a famous myth involving geese that granted them their name. The barnacle goose is a species native to Europe but in the days when spontaneous generation was accepted, nobody knew how they reproduced. The geese migrate to the arctic to mate and lay eggs, but nobody knew that at the time. A common myth arose where goose barnacles attached to driftwood were said to be the remnants of goose trees, where the barnacle would grow and eventually release a fully-grown goose. This myth is where the name barnacle came from. The crustaceans were named after the goose.

(image: a drawing of a goose tree)

#wet beast wednesday #barnacles #crustacean nation #crustaceans #parasite #biology #zoology #marine biology #marine life #that one parasite that force-femmes crabs

[luckyraeve]

Tagged by @glacialispictorem

50 (yes fifty) Things You’ve Never Been Asked…. Oof! Fifty is a LOT, but since I don’t do these very often, why not? *shrugs*

1. What is the colour of your hairbrush? Red

2. Name a food you never ever eat. Crab. Had a weird reaction to it once, so haven’t tried it again in case it becomes a severe allergic reaction.

3. Are you typically too warm or too cold? Both. I’m never happy.

4. What were you doing 45 minutes ago? Eating breakfast and watching Youtube.

5. What is your favourite candy bar? *mild panic* I like so many...uh...but one I have in my cupboard right now is a Twix bar, so yeah, Twix, I guess.

Putting the rest under a Read More bc looooong...

6. Have you ever been to a professional sports game? I have. I do not care for sporps, so the experience was meh.

7. What is the last thing you said out loud? “Piper, you’re a stinky STINKY girl!” (my cat just used her litter box and yeah *gags*)

8. What is your favourite ice cream? Chocolate.

9. What was the last thing you had to drink? Arizona Green Iced Tea

10. Do you like your wallet? Yes. It’s a Super Mario wallet, and yes I am an adult woman *pulls drivers licence out of child’s Mario wallet to prove age*

11. What was the last thing you ate? Bacon, eggs, toast, green grapes.

12. Did you buy any new clothes last weekend? Nope.

13. The last sporting event you watched? No sporps.

14. What is your favorite flavor of popcorn? Butter and salt, but kettle corn is good too.

15. Who is the last person you sent a text message to? My mom.

16. Ever go camping? Yes, it’s okay, I guess. Not something I want to do often tho.

17. Do you take vitamins? Sporadically. Not sure they are actually doing anything tho.

18. Do you go to church every Sunday? Nope.

19. Do you have a tan? Only in the summer.

20. Do you prefer Chinese food over pizza? *panic INTENSIFIES* I like both, but if forced to choose, Chinese food.

21. Do you drink your soda with a straw? Only if it’s takeout.

22. What color socks do you usually wear? The brighter the colour(s), the better!

23. Do you ever drive above the speed limit? Not lately, as I can’t afford a car, but I did, just a little, back in the day.

24. What terrifies you? parasitic organisms @___@

25. Look to your left, what do you see? My stinky cat, sound asleep.

26. What chore do you hate most? Cleaning the bathroom.

27. What do you think of when you hear an Australian accent? Mr. Sunday Movies / The Weekly Planet podcast. Love those guys! <3

28. What’s your favorite soda? Pepsi is my usual, but I also really like Cherry Pepsi, Black Cherry soda, and Pineapple soda.

29. Do you go in a fast food place or just hit the drive? In. I don’t have a car.

30. What is your favourite number? 8

31. Who’s the last person you talked to? My parents.

32. Favourite cut of beef? Um, whatever I can stir fry with...? Steve Rogers

33. Last song you listened to? Femmes Fatales by Yoko Shimomura (Parasite Eve OST)

34. Last book you read? It’s been so long, I don’t remember.

35. Favourite day of the week? Saturday/Sunday (or any holiday I don’t have to work).

36. Can you say the alphabet backwards? I sure can’t!

37. How do you like your coffee? I don’t.

38. Favourite pair of shoes? Running shoes. If my feet gotta be in a prison, then it has to be a comfy prison.

39. The time you normally get up? Between 8 and 9am (unless it’s a work day, then it’s earlier).

40. What do you prefer, sunrise or sunsets? Sunsets. Sunrises are overrated when you’ve had to wake up at 5am to get to work for the past 5 years.

41. How many blankets on your bed? One.

42. Describe your kitchen plates. Apple green coloured.

43. Describe your kitchen at the moment? Mostly tidy, just a few dirty dishes.

44. Do you have a favourite alcoholic drink? I used to enjoy fruity drinks made with rum or vodka, but I don’t like drinking anymore.

45. Do you play cards? Just Uno when my niece visits.

46. What colour is your car? I don’t have a car.

47. Can you change a tyre? Maybe...? I learned how to a long time ago. I’m sure youtube would be very helpful in that area now.

48. Your favourite state? Um, not sure what kinda state we’re asking about here, like, state of mind, solid/liquid/gas, United State? :/

49. Favourite job you’ve had? The one I have now bc it pays the most and I don’t hate it, so yay!

50. How did you get your biggest scar? Elective surgery.

Not tagging anyone bc it’s looooong, but for anyone who wants to do it, go nuts! :D

#meme #tagged meme #questions meme #about me