The crown-of-thorns starfish (Acanthaster planci) is named for the brightly colored spikes that coat the legs. A. planci can grow up to 16 inches across and can have between 12 and 19 legs. The spikes coating A. planci hold poison that can cause temporary paralysis at the sting site and can also cause nausea in humans. A. planci can also regrow arms. At the end of each of the arms is an eyespot that can detect light and darkness, but can not detect color and shape (Fisher 2011). A. planci preys on coral and a single starfish can eat up to 10 sq. meters of coral each year. A. planci kills approximately 161 sq. cm. per day in the winter and 357-478 sq. cm. per day in the summer. In order to eat the coral, A. planci pulls its stomach out …show more content…
The small shrimp, Hymenocera picta, is a general predator of all starfish and has been found to prey on A. planci at some locations. Pherecardia striata can only attack damaged A. planci and cause its death. Therefore, P. striata is regarded as a scavenger rather than as a predator. A. planci attracts many other scavengers who are able to tolerate A. planci’s horrible taste for the chance at a food source (Fisher 2011). There is increasing evidence in numerous scientific studies that show that widespread marine species can be highly structured genetically and may speciate very quickly. Genetic differentiation of populations in the Indian and the Pacific Oceans has been reported for coconut crabs (Lavery et al. 1996), the starfish Linckia laevigata (Williams and Benzie 1997), butterfly fish (McMillan and Palumbi 1995), damsel fish (Lacson and Clark 1995), and the mangrove Avicennia marina (Duke et al. 1998). Despite the evidence of high gene flow within the Indian and the Pacific Oceans, this still holds true. This suggests that there is high dispersal over large areas. However, there is limited dispersal between zones. Contrary to the aforementioned data about other species, there is little genetic divergence of sibling species of sea urchins (Echinometra spp.) in the Pacific Ocean. This suggests recent speciation, but it also suggests rapid dispersal after speciation (Palumbi 1994). These discrepancies of results show that there is a need to
The purpose of the experiment was to investigate the physiological effects of epinephrine on the heart rate of the organism called Daphnia magna as well as to calculate the median effective dose. Daphnia magna are arthropods found in pools of freshwater or areas where freshwater meets seawater in Western Europe and the Atlantic Coastline of the United States (Elenbaas, 2013). They are about two to five millimeters in length and have a transparent shell. Their heart is located on the dorsal side of the organism and the gills are on the ventral side. Daphnia magna also has two antennae and six appendages that are used to bring food and oxygen to the organism’s gills and produce movements.
The removal of predators such as excessive fishing and shell collecting, allowing populations of the Crown of Thorns Starfish to increase beyond natural levels. Predators such as the giant triton snail, sweetlips emperor feed to some extent feed on crown-of-thorns starfish. Juvenile starfish are likely to be eaten by their predator fish about six months after they begin feeding on corals. If numbers of
The Callinectes sapidus also known commonly as the Maryland Blue Crab, is a crustacean found in the Chesapeake Bay. The blue crab is found in aquatic environments, most often in estuaries. It characterized by it’s blue claws. The blue crabs undergo a life cycle of: zoeae, megalop, juvenile, and adulthood. The blue crab’s hard shells serve as a protective barrier for external dangers. The Callinectes sapidus comes from the order of Decapods, whereby it’s carapace has now evolved to be better suited for swimming. Of interest is the blue crab’s mating
Echinoderms such as starfish, sea cucumbers, and urchins are identified by their symmetry and central mouth. This species is found decorating the coral reefs by their variety of color and sizes. Because some of these animals like to burrow in the sand, they can supply oxygen to some of the depths in the ocean. Echinoderms are a staple food in many sea animals diet.
Along the coasts of rocky beaches, an intricate ecological community inhabits the ‘rocky intertidal’ areas. The variety of rocks is home to an array of slimy, squishy, and colorful organisms. This intertidal community is comprised of nine species: three different algae, three stationary filter-feeders, and three mobile consumers. The three algae, Nori Seaweed, Black Pine, and Coral Weed, are the community’s producers and inhabit the bottom of the food chain. The next three species are stationary consumers. They are Mussel, Goose Neck Barnacle, and Acorn Barnacle. Because of their consumer status, they are more competitively dominant than algae. The last three components are the mobile consumers: Whelk, Chiton, and Starfish. They
The red algae Polysiphonia sp. 1 does not survive well in areas along the reef where the damselfish are not present because it is often grazed on and does not survive as well as other algae. It holds a mutualistic relationship with damselfish because while these fish do graze on the algae they do not consume it completely and allow the algae to continue to grow as well. Eighteen damselfish species were used in this study in different territories throughout the Indo-West Pacific to study their relationship with the red alga. Polysiphonia sp. 1 was found in the central Indo-Pacific but was low in abundance from the Great Barrier Reef and Mauritius, and the algae were also found in territories of fishes from the African coast. Other species of the clade in this alga were found only where damselfish inhabited the area as well. The results showed that the cultivation mutualism was maintained throughout the Indo-Pacific even though variations were seen among the mode of cultivation. From this it can be gathered that damselfish in different regions have different methods of cultivating the algae and this in turn affects the algae
The Caribbean Spiny Lobster, a uniquely adorned decapod, is found in subtropical to tropical waters, inhabiting rocky crags to sponges to sea grass. A carnivorous species, they will feed on gastropods, sea urchins, worms, and crustaceans. In addition to this, they are also important aquatic scavengers, aiding in the process of decomposition of dead organisms that fall to the ocean floor (Kanciruk 1980). Commonly fed on by moray eels and nurse sharks, they play a significant role in the food chain for not only marine species, but for humans as well. According to the FAO Fisheries and Aquaculture Department, this is one of the most important Palinurid species that is harvested in American waters due to high demand (Holthuis 1991). The economic
testudinaria obtained from the Atlantic in the Georgia coast (GA00 GA01),from the Gulf Coast off of Florida (FL) and from the Pacific Coast off of Mexico (B). We also analyzed genotypic data in the form of three microsatellite loci from each of three Pacific populations: Santa Barbara, Mexico, and Hawaii. We have asked (i) whether there is evidence to support that there is more than one Barnacle species; (ii) what are the relationships of the Barnacle populations; and (iii) is there evidence of gene flow among the Pacific populations, are they in H-W equilibrium, and is there evidence of reproductive
The shell of Limulus polyphemus frequently serves as substrate for a large number of epibionts, such as barnacles, mussels, oysters, polychaetes, slipper limpets, algae and other encrusting invertebrates ( Botton, 2009; Botton et al. 2015). The term epibiosis is used to describe a non-symbiotic, facultative association between the substrate organism and sessile animals (epizoans) or epiphytic algae (Botton, 2009). Using horseshoe crabs as a substrate may be advantageous for the epibionts in that it aids in gene dispersal and feeding opportunities (Botton & Shuster, 2003). Because horseshoe crabs are migratory, any of the organisms that live on them must be able to survive the same wide range of temperatures and salinities as their hosts (Botton, 2009).
True starfish are classified in the Asteroidea, a group of echinoderms. True starfish have no sharp demarcation between arms and central body, and they move using tube feet rather than wriggling movements of the whole arms. True starfish and ophiuroids shared a common ancestor in the Ordovician. Most starfish are predators, feeding on sessile or slow-moving prey such as mollusks and barnacles. (example: crown-of-thorns starfish, Acanthaster specializes on corals, and may do considerable damage to coral reefs.) Many, but not all, starfish are able to turn a portion of their stomachs out through the mouth, and thus digest food outside of the body.
Commonly, the red king crab is described as a generalist feeding decapod (Britayev et al. 2010). It displays a number of different feeding strategies, such as grasping and tearing apart of larger prey, scooping-up sediment by the lesser chela and sieving it through the third maxillipeds, and crushing scallops and picking out only the flesh (Jørgensen 2005). The heavy mastication of food items in crustaceans makes the identification of prey during stomach analysis difficult, and soft tissue may be underestimated in field studies (Sarda & Valladares 1990). This can introduce bias towards calcified and hard prey items, as these are more frequently identified in crab stomachs. The most frequent prey groups identified in the red king crab in Norwegian
This information is incredibly alarming as lionfish are a generalist species, consume a great variety of prey, lack predators and disease in their invaded range, as well as possess venomous spines (Albins, 2015; Albins & Hixon, 2013; Bayraktarov et al., 2014; Bejarano et al., 2015; Carberry, 2014; Cote et al., 2013; Cure, McIlwain, & Hixon, 2014; Edwards et al., 2014; S. Green, 2014; Jud et al., 2015; Valdivia, Bruno, Cox, Hackerott, & Green, 2014). These factors strongly suggest lionfish have the potential to degrade coral reef habitat and water quality, decrease biodiversity, deplete economically important fish stocks, and decrease tourism (Albins & Hixon, 2013; Cure et al., 2014; Morell, 2010; Ruiz-Carus et al., 2006; Valdivia et al.,
Some marine species achieve great dispersal distances and range expansions with the assistance of floating propagules such as rafts, which provide habitat for the duration of their time afloat (Edgar 1987; Jokiel 1990; Helmuth et al. 1994; Thiel et al. 2005). The distance that propagules disperse may control the demographics of marine populations, in addition to governing the rates of colonization, range expansion, and genetic exchange(Kinlan et al. 2003; Donald et al. 2005). Biologists also speculate that passive rafting plays a key role in colonising isolated environments such as islands (Kinlan et al. 2003; Fraser et al. 2011), with many ‘non-dispersive’ coastal species incapable of reaching these locations independently (Jokiel 1990; Kinlan
The Acanthaster planci, better known as the crown-of-thorns sea star, is a marine invertebrate and one of the largest species of sea stars known in the world. It is endemic to the coral reefs in the Indo-Pacific region, finding habitat within the Great Barrier Reef, Australia. Over the past several decades, Acanthaster planci has gained a global infamous reputation for its devastating outbreaks affecting the Great Barrier Reef. However, when looking further into the behaviours, predation, and diet of the crown-of-thorns it is understood that it also plays a vital ecological role within the reef’s ecosystem.
In Chapter 23, we talked about the many different ways that a population can evolve over time. Relating to the topic of this chapter, an academic journal published by Karasawa et al. (2015) discussed how different species of scorpions existed on different islands of Japan and Taiwan. From what we previously know about evolution, these scorpions could have been the same species at an early point in history but due to the founder effect, one species might have established a new population. This could have been a result of the islands being separated by the Kerama Gap, a specific waterway that separates these two species (Karasawa et al. 2015). It is a possibility that these species of scorpions have a common ancestor and because of the changing