This genus was described by Linnaeus in 1758. Although there are no synonyms for this genus, there are several cases of synonymy among species and subspecies (Roskov, et al., 2017). Since being described, all cone snails have traditionally been placed in this single genus. Many studies have been done, and revised and updated phylogenies are continuously being published. In addition, multiple studies agree that one species, Conus californicus, is the sister taxa to all other cone snails. Some studies even suggest putting that single species into its own genus: Californiconus (Puillandre, et al., 2015; Puillandre and Tenorio, 2017). Of the hypotheses in the field, some are in favor of keeping as one genus, and others that say there are as many as 127 genera, and many more subgenera. Puillandre, et al. support a system of four genera and 71 subgenera for this group. This system is well supported by both morphological and molecular data and is popular in the field. Many of the hypotheses that have been suggested regarding use only shell and radula variation data, which alone is not a good indicator of evolutionary relationships (Puillandre, et al., 2015). (Puillandre and Tenorio, 2017; Puillandre, et al., 2015; Roskov, et al., 2017)
When Conus cingulatus, the male buried himself under the sand, while the female roamed the tank immediately following mating. These and other systems are less studied across , but other species from family Conidae and other closely related families (Buccinidae and Fasciolariidae) have been studied and have shown comparable results. It is therefore reasonable to assume that this system is true across most of (Cosel and Kohn, 2013; Cruz, et al., 1978). (Cosel and Kohn, 2013; Cruz, et al., 1978)species mate, they do so throughout the year and both sexes mate with multiple different individuals in their lives. The snails will secrete pheromones that attract mates towards them, and a male will approach a female. It is important to know that do not follow mucus trails to sense and find mates. As mating begins, the male goes to the female’s right, anterior side where he climbs onto the shell and extends his penis. He begins to touch and sense the shell while moving to the posterior end of the female’s shell. When he reaches the end, the penis is used to sense and find the opening to the mantle cavity. The female reproductive structures are near this opening. The male inserts his penis, and the couple remain motionless for 20-25 minutes while insemination occurs. In
Species of C. geographus have a noticeable increase of oviposition in the month of April. Generally, across all , as females get older their shell's annual growth rate decreases and rate of ova production increases. This allows more energy to be put into reproduction. In C. geographus, females produce about 6,000 ova by the time they are ten years old. Development time, that is from oviposition to hatching, is species specific and varies across . In Hawaiian species, this time typically ranges from 11-26 days (Cruz, et al., 1978; Perron, 1981; Perron, 1983). (Cruz, et al., 1978; Perron, 1981; Perron, 1983)will mate and spawn throughout the year, and egg cases are laid in masses containing many eggs. Females of
Most of the maternal reproductive energy is focused towards the egg cases in which embryos are laid. Around 50% of energy designated to reproduction is used in making these egg cases, consisting mainly of proteins. This makes sense when considering certain species make cases of various thickness and strength. The species that spend the most time developing will have thicker egg cases, and the species that develop the fastest have thinner egg casings. This provides protection from predators, and aids in prevention of desiccation (some egg cases may be laid in places that are exposed to air in low tide). The remaining 50% of reproductive energy is used towards nutrition for developing embryos (post-fertilization, pre-oviposition), as well as providing food for offspring (post-hatching, pre-independence). Although there is information that (Perron, 1981; Perron, 1983)begin mating at about two years old, there is little knowledge regarding how long parents will care for their offspring (Perron, 1981; Perron, 1983).
Conus pennaceus is typical in that their lifespan is limited to around 10 years, while Conus quercinus and C. flavidus live much longer; the former reaching an age of 17 while the latter reaches 20 (Perron, 1986). (Perron, 1986)gastropods live for a relatively long time. Most species live to about 10 years, with some species exceeding that. One species,
species are social, motile gastropods that are primarily active at night and dormant during the day. During daytime, these snails hide in algae or under rocks and coral. This happens because prey is also more active and plentiful in the environment during the night, so the mollusks must wait until then to feed. Another reason is that almost all of the smaller species are unable to hold themselves in strongly moving waters, such as waves, and limit their activity to after the tide has receded. In the lab, Kohn observed snails active at night even while the habitat was lit. He suggested that it was the natural daily rhythm of the organisms to be active at that time, regardless of the lights (Kohn, 1959).
These snails have a proboscis that is very important for feeding and reproductive behaviors. This organ is used for sensing the environment (finding food) and has a modified radular tooth that is used to inject a fast-acting venom into prey (Puillandre, et al., 2015). The proboscis is used to sense species-specific chemical cues and physically touching the mate during mating (Kohn, 1961). Snails also respond to touch.
Cone snails have a highly developed chemosensory system. This system is primarily for feeding, and captive specimens were observed immediately moving towards food that was placed in the habitat. This chemosensory system is also important to reproduction. Prior to mating, (Kohn, 1961)snails use the tip of the proboscis to detect chemicals in the water secreted by members of the opposite sex, and move towards them (Kohn, 1961).
There are three main feeding types in C. flavidus, that eat enteropneust hemichordates Order Enteropneusta. Among the vermivorous species, many consume only polychaete worms Class Polychaeta. Some species, such as C. pennaceus, are molluscivorous and feed on other marine gastropods, including other species. The piscivorous species, such as C. californicus prey on prickleback fish (Cebidichthys violaceus and species of Xiphister) and others (Remigio and Duda, 2008; Stewart and Gilly, 2005). (Remigio and Duda, 2008; Stewart and Gilly, 2005). There are piscivorous, vermivorous, and molluscivorous species, and some, such as
In addition to these types of feeding there are two main feeding strategies. In Conus striatus, the radular tooth at the end of the proboscis remains attached after injecting prey with venom. The proboscis then retracts and pulls prey into the mouth. In Conus abbreviatus and Conus ebraeus, the radula tooth is left in the prey and the snail moves toward the prey, while expanding its mouth to ingest it. In C. pennaceus, up to six radular teeth may be left in a single victim. In C. californicus and other piscivores some do not inject the radula at all, and others that will attack the prey with its proboscis multiple times (Kohn, 1959; Stewart and Gilly, 2005). (Kohn, 1959; Stewart and Gilly, 2005)
In molluscivorous C. pennaceus and Conus textile, when the prey has a small shell it will be ingested and regurgitated. In large-shelled prey, the venom is injected (usually in the foot) and loosens the body of the organism from its shell, and the soft body is consumed (Kohn, 1959). (Kohn, 1959)
This group is not highly preyed upon, but it is likely that both parrot fish (Family Scaridae) and zebra eels (Gymnomuraena zebra) prey on . There are also species that prey on other gastropods including other members of their genus; these include C. pennaceus and C. textile. In the lab, Cymatium gastropods and Asterope seastars preyed on , with reason to believe this happens in nature as well. In the past, have been preyed upon by Menippe mercenaria and it is theorized that this group significantly influenced the evolution of . In addition to this species, other crabs are known to tear the egg-cases and prey on developing embryos (Kohn, 1959; Perron, 1981; Kosloski and Allmon, 2015). (Kohn, 1959; Kosloski and Allmon, 2015)
As predators, (Kohn, 1959)play a big role in their ecosystems. They prey on fish, polychaetes, even other mollusks. They are also a food source to the groups that prey on them. With few predators, is an extremely successful group (Kohn, 1959).
In these snails, there is a very interesting mutualistic relationship between actinomycetes. In this genus, there were high amounts of these bacteria, a total of 229 that were morphologically distinct across three species of (Peraud, et al., 2009). The goal was to gain new information on bioactive bacteria in hopes of finding better drugs and medicine, although at the time of the study they were unable to determine the association between these bacteria and the venom of this genus (Peraud, et al,. 2009).
Although small in size, (Peters, et al., 2013)species have been very important to humans throughout history. There is a global market established for the trade of shells, that range from amateur collectors to professional traders. There are also local markets that sell to tourists and support the economy, or just individual households. This group is also sold as a food source in the local markets. To these people, species are important. are also being targeted for drug research more recently, and scientists are looking into ways of creating more effective and less addictive drugs (Peters, et al., 2013).
There is only a single known adverse effect this group has on humans. This is that their venom is highly toxic to humans, and some have died from being bitten. The geography cone, Conus geographus, causes most - related human deaths (Peters, et al., 2013). (Peters, et al., 2013)
There are 632 species of Conus lugubris, Conus mordeirae, and Conus salreiensis of Cape Verde, Africa. Eleven of these species are endangered, including Conus clover, Conus hybridus and Conus Mercator of Senegal, West Africa. 27 are vulnerable, including Conus compressus and Conus thevendarnesis of Australia. Another 26 are near threatened and 87 are data-deficient. The status of the remaining 478 species is of least concern (Peters, et al., 2013). (Peters, et al., 2013)studied in a summary and analysis of conservation status of the genus. According to IUCN Red List, three species are critically endangered. These are:
Fossils of (Hendricks, 2015)have been acquired from the Neogene period and are about 6.6-4.8 million years old. There are over 1,000 described fossil species of , but Hendricks suggests that many are synonymous and the reason for that is their shell morphology and coloration cannot be studied, which prevents accurate classification. These shells do not show any original color patterns under normal light because of their age, however under UV light, Hendricks found that 60% revealed original color patterns. After being photographed in UV light, the image can be photo-edited to show the original color. This is being used in order to more clearly understand fossil mollusks, including those of (Hendricks, 2015).
Triston Childs (author), Colorado State University, Genevieve Barnett (editor), Colorado State University.
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
areas with salty water, usually in coastal marshes and estuaries.
an animal that mainly eats meat
uses smells or other chemicals to communicate
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
parental care is carried out by females
union of egg and spermatozoan
A substance that provides both nutrients and energy to a living thing.
fertilization takes place within the female's body
the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
eats mollusks, members of Phylum Mollusca
having the capacity to move from one place to another.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
an animal that mainly eats fish
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.
mainly lives in oceans, seas, or other bodies of salt water.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
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