LeslieH
Well-known member
See or have a good pic of an nifty invert? Why not share it? Post it here with some comments about why you think it's cool.
I'll start with a great shot of Pagurus edwardsi, a colorful hermit crab from Chile, by Art Anker. The yellow structures are the egg sacs of the parasite Peltogasterella gracilis.
Peltogasterella and related species belong to an incredibly bizarre group of barnacles called Rhizocephala. They don't have the hard calcium plates typical of most barnacles. Instead, the planktonic juvenile females attach to the body of their victims. Some do so by clinging to the host's antennae. At the start the juveniles have exoskeletons like all crustaceans do but after making the entrance hole the barnacles ooze out of their exoskeletons & into the host. They essentially become shapeless blobs of tissue with rootlike structures that extend throughout the host's body to absorb nutrients. The only sign of their presence are these structures that contain eggs called externa. Males are tiny, free-living things, that will attach to the egg sacs & inject themselves into the sacs where they transform into sperm-producing cells.
Not only do the barnacles steal nutrients from the hosts, they also control the hosts' reproductive systems & even their behavior. Hosts often become sterile so the energy they would put into gamete production goes to the parasite. When the barnacle's eggs are mature the host will treat the eggs as their own.
With hermit crabs the parasite's externa are usually hidden from view. Not so with shrimp or true crabs. Often the externa emerge through the gills or the shell of the host - Strange Shrimp in Lembeh Strait | Tony Wu's Underwater Photography Blog
Occasionally an infected crustacean will show up in someone's tank. If it does - like on the poor Lysmata amboniensis in this thread Problem with our Cleaner Shrimp? - Reef Central Online Community - what should you do? The parasites are very host-specific. You can't eliminate the parasite without killing the host, unfortunately. If it's a new purchase take it back to the LFS, explain the problem and get your money back. Otherwise dispose of it humanely. It's better to remove the host rather than risk having juveniles that could infect other animals.
I'll start with a great shot of Pagurus edwardsi, a colorful hermit crab from Chile, by Art Anker. The yellow structures are the egg sacs of the parasite Peltogasterella gracilis.
Peltogasterella and related species belong to an incredibly bizarre group of barnacles called Rhizocephala. They don't have the hard calcium plates typical of most barnacles. Instead, the planktonic juvenile females attach to the body of their victims. Some do so by clinging to the host's antennae. At the start the juveniles have exoskeletons like all crustaceans do but after making the entrance hole the barnacles ooze out of their exoskeletons & into the host. They essentially become shapeless blobs of tissue with rootlike structures that extend throughout the host's body to absorb nutrients. The only sign of their presence are these structures that contain eggs called externa. Males are tiny, free-living things, that will attach to the egg sacs & inject themselves into the sacs where they transform into sperm-producing cells.
Not only do the barnacles steal nutrients from the hosts, they also control the hosts' reproductive systems & even their behavior. Hosts often become sterile so the energy they would put into gamete production goes to the parasite. When the barnacle's eggs are mature the host will treat the eggs as their own.
With hermit crabs the parasite's externa are usually hidden from view. Not so with shrimp or true crabs. Often the externa emerge through the gills or the shell of the host - Strange Shrimp in Lembeh Strait | Tony Wu's Underwater Photography Blog
Occasionally an infected crustacean will show up in someone's tank. If it does - like on the poor Lysmata amboniensis in this thread Problem with our Cleaner Shrimp? - Reef Central Online Community - what should you do? The parasites are very host-specific. You can't eliminate the parasite without killing the host, unfortunately. If it's a new purchase take it back to the LFS, explain the problem and get your money back. Otherwise dispose of it humanely. It's better to remove the host rather than risk having juveniles that could infect other animals.
