CATDOLL : CATDOLL: Parasites that attach to sea snail shells

1. Parasites attached to sea snail shells

It should be barnacles, which are parasitic on many shells.

2. What creatures live thousands or even tens of thousands of meters below the sea?

Deep-sea organisms can be divided into three categories according to their lifestyle: planktonic, swimming and benthic. Planktonic organisms consist of some species of bacteria, protozoa, coelenterates, crustaceans, chaetognaths, etc., and the species and number of organisms are relatively small. The number of organisms usually decreases significantly with the increase of water depth. The mass of medium-sized plankton in the Kuril Islands-Kamchatka waters of the Pacific Ocean exceeds 100 mg per cubic meter at a depth of 200 to 400 meters, but it is less than 1 mg below 3,000 meters. For the same type of zooplankton, individuals mostly live in shallow waters when they are small, and live in deep waters when they are larger. For example, some species of copepods such as the genus Daphnia and the genus Daphnia can reach a maximum size of 17 mm at a depth of 2,000 meters, and as the water depth becomes shallower, the size of the individual also decreases. Deep-sea zooplankton are mostly omnivorous or carnivorous. The vertical movement of zooplankton plays an active role in the vertical transfer of nutrients. The main types of zooplankton are: ① Crustaceans, the most important of which are some species of copepods such as Daphnia pulex, Daphnia pulex, Daphnia pulex, Daphnia pulex, etc. (the largest individual can reach 17 mm). Then there are mysids, krill, amphipods and decapods, as well as animals of the class Ostracoda. ② Coelenterates, including scyphozoa and tube jellyfish. They do not have a polyp stage in their life history. Individuals are generally large, up to 25 cm in diameter, mostly chestnut and purple, and can glow. ③ Olive green cells, cells with a length of 10 to 15 microns. Some scholars believe that they belong to flagellates. At a depth of 3,000 to 4,000 meters, the density of such cells can still reach 25,000 to 50,000 per liter. They can also often be picked up in the intestines of some planktonic crustaceans, and their origin is still unclear. nbsp;nbsp;nbsp;nbsp; Swimming organisms are mainly fish, followed by squid, octopus and shrimp (Figure 1). Among the more than 1,000 species of ocean fish, about 150 live in deep water. Among them, the most species belong to the suborder Ceratopogonids, with about 80 species. There is a handle-like protrusion on the dorsal side of the head of deep-sea fish, the top of which can emit light and is used as bait and lighting. The mouth is large. The weight of female fish can reach 6 to 8 kilograms, while the weight of male fish is only a few grams (Figure 2). The head of the male fish drills into the epidermis of the female fish to absorb nutrients and forms a small crack. During the spawning period of the female fish, the male fish produces sperm in the bag for fertilization. The fish do not form groups, and the distance between individuals is about 30 meters. There are also many eels in the deep sea, such as the Hastelloy sac-throated fish and the wide-throated fish. The fish body is slender and the mouth is particularly large (Figure 3). Some eel larvae swim to shallower water layers and return to deep water when they become adults. nbsp;nbsp;nbsp;Among deep-sea fish, the genus Cynomorium has the largest number of individuals. The fish are small, only 5 to 6 cm long, with a large dark brown head, and their gills can filter zooplankton. They do not form groups, and individuals keep a distance of about 3 meters between them. nbsp;nbsp;nbsp;There are many species of fish near the bottom of the deep sea, and the individuals are also large. For example, the sleeping shark can reach 7 meters in length and lives by predation. Some deep-sea fish can often swallow food larger than themselves (Figure 4). There are fewer species of deep-sea cephalopods, and some octopuses are adapted to deep-sea life and have no eyes. nbsp;nbsp;nbsp;Benthic organisms nbsp;nbsp;The biomass of deep-sea benthic organisms decreases with water depth (see table). There are many benthic organisms at a depth of 2000 to 3000 meters. As the water depth increases, its composition also changes, and shallow water species are gradually replaced by deep water species. Usually 200, 3000 and 6000 meters are turning points. In the abyss above 10,000 meters, there are still benthic organisms. The species that have been discovered include: foraminifera, anemones, polychaetes, isopods, amphipods, bivalves and sea cucumbers. ① Micro-benthic organisms, the size of which is between 2 and 40 microns, mainly live on the surface of the seabed sediments. Including fungi, variable bacteria, yeast cells, sarcoptes, saccharomyces, ciliates, foraminifera, etc. According to a survey at a depth of 5498 meters in the central North Pacific, the number of individuals on the surface of the sediment is about 24,000 per square centimeter, while in a 0.5 cm sediment sample, it is only 1150 per square centimeter. ② Small benthic organisms, the size of which is between 42 and 1000 microns, live in the same waters, and the number of individuals is about 3 orders of magnitude less than that of micro-benthic organisms. Small benthic organisms mainly include foraminifera, hydra, turbellarians, nematodes, gastrotriche, zoostomata, tardigrades, oligochaetes, protochaetes, sea mites, ostracods and some species of the order Daphnia. Among them, nematodes are the main species, with a large number of individuals, accounting for about half of the total number of animals. ③ Large benthic organisms, with an individual size of more than 1000 microns, include most phyla of invertebrates, such as sponges, coelenterates, star worms, tracing branchia, enterobranchiate, worms, annelids, mollusks, arthropods, echinoderms and brachiopods, as well as a small number of chordates (such as sea squirts) and benthic fish. nbsp;nbsp;nbsp; Deep-sea sponges are large (up to 1 meter) and often have a long handle inserted into the bottom mud. Sea anemones can live in the abyss of up to 10,000 meters deep, and some of them are attached to other animals or build tubes to live. nbsp;nbsp;nbsp;Polychaetes are important benthic organisms in both shallow and deep waters. There are a total of 8 species of large benthic organisms collected in the deep sea of ​​the western central Pacific Ocean, including 4 polychaetes, namely, the snout worm, the sea pupa, and one each of the Microcephala and the Constricta; the remaining 4 species are beautiful crown leaf corals, bone-margined walnut clams, scallops, and an animal of the suborder of gammarids. nbsp;nbsp;nbsp;Each class of the phylum Echinodermata has deep-sea species, most of which are benthic feeders, and some starfish are carnivores that prey on foraminifera, polychaetes, and mollusks. In places where organic matter is abundant, sea cucumbers are often the dominant species, and the individuals are also large (some can reach 0.5 meters). Some sea cucumbers living in the deep sea have leaf-shaped "feet",

3. Biological Competition Ecology

Three biological chains

4. Who knows what the parasites on the outside of scallops are?

If it is on the outside of the shell, it may be an oyster or oyster parasite on it. If it is around the meat, I think it is the excrement of the scallop. It is not edible, it is best to remove it and clean it.