Southern Sea Otter Lecture Notes PDF

Southern Sea Otter Southern sea otters, also known as California sea otters, live in the waters along the central California coastline. Its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. It preys mostly on marine invertebrates such as sea urchi...

Southern Sea Otter Southern sea otters, also known as California sea otters, live in the waters along the central California coastline. Its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. It preys mostly on marine invertebrates such as sea urchins, various mollusks and crustaceans, and some species of fish. Unlike most other marine mammals, the sea otter has no blubber and relies on its exceptionally thick fur to keep warm. High energetic requirements of sea otter metabolism require them to consume at least 20% of their body weight a day. it is a keystone species, controlling sea urchin populations. Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals living in a fraction of their historic range. Between 1938 and 2009 the population of southern sea otters increased from 50 to 2790 but still endenger list. (1) How do species interact ? Competitive species Competition is a relationship between organisms that strive for the same resources in the same place. The resources might be food, water, or space. There are two different types of competition: 1. Intraspecific competition occurs between members of the same species. For example, two male birds of the same species might compete for mates in the same area. This type of competition is a basic factor in natural selection. It leads to the evolution of better adaptations within a species. 2. Interspecific competition occurs between members of different species. For example, predators of different species might compete for the same prey.(2) Resource partitioning helps in dividing limited resources so that different species utilise the different parts of a resource, slightly different resources or the same resource at different times or at different places in order to meet their requirements. Kelp forest Kelp are large brown algae (Phaeophyta) that live in cool, relatively shallow waters close to the shore. Why are kelp forests important? Kelp forests harbor a greater variety and higher diversity of plants and animals than almost any other ocean community. Many organisms use the thick blades as a safe shelter for their young from predators or even rough storms. These underwater towers of kelp provide food, shelter, and protection for all kinds of marine life Threats to kelp forest from predators and climate changes Numerous natural impacts as well as human activities, affect kelp forest environments. The factors influencing kelp forest stability are diverse: kelp harvesting; grazing by fishes, sea urchins, and crustaceans; plant competition; storms sedimentation, pollution and rising temperatures in the water.(3) Parasitism A relationship between two organisms in which one organism (the parasite) benefits and the other (the host) is harmed. Parasites derive nutrition from their host and may also gain other benefits such as shelter and a habitat in which to grow and reproduce. The parasite lives on or in the body of the host. The lamprey uses its rough tongue to rasp away the fish’s flesh so it can feed on its host’s blood and body fluids. (4) Mutualism Mutualism, association between organisms of two different species in which each benefits. Mutualistic arrangements are most likely to develop between organisms with widely different living requirements. Several well-known examples of mutualistic arrangements exist. The partnership between nitrogen-fixing bacteria and leguminous plants is one example. In addition, cows possess rumen bacteria that live in the digestive tract and help digest the plants the cow consumes Anemonefish and sea anemones have a symbiotic, mutualistic relationship, each providing many benefits to the other. The individual species are generally highly host specific. The sea anemone protects the anemonefish from predators, as well as providing food through the scraps left from the anemone’s meals and occasional dead anemone tentacles, and functions as a safe nest site. In return, the anemonefish defends the anemone from its predators and parasites.(5) Most types of bacteria aren’t harmful. Some are even good for you. These helpful bacteria are mainly located on your skin or in your gut or digestive system. They’re called resident flora, or your microbiome, which are groups of microbes living in and on your body. Gut bacteria keep you healthy by absorbing nutrients, breaking down food and preventing the growth of harmful bacteria. Commonsalism Commensalism is a type of relationship between two living organisms in which one organism benefits from the other without harming it. A commensal species benefits from another species by obtaining locomotion, shelter, food, or support from the host species, which (for the most part) neither benefits nor is harmed. Commensalism ranges from brief interactions between species to life-long symbiosis. Ex : Nurse plants are larger plants that offer protection to seedlings from the weather and herbivores, giving them an opportunity to grow.(6) MCQ 1- Southern sea otter preyon ………… (fish only ,mollusks only ,crustaceas only ,all of them ) 2- Sea otter depend on …… ……. to keep it warm (blubber ,thick fur ,thin fir ,hairs) 3- Sea otter is a key stone species controlling population ……….. (sea urchin ,sa bass ,sea horse ,all of them,) 4- Is a Relation between two species both of them benefit from each other……….. (commensalism ,competition ,mutualusm) 5_ is a relationship between two species, each species affected negatively (commensalism ,mutually, predation, competition) 6_ is relationship between two species , one species benefits,one un affected (commensalism ,mutualism,predation competation) 7- resource partitioning help in ………. limited resources, so that different species utilize different parts of resource (competition, predation, dividing,non of them) 8-kelp are large brown………. (algae ,bacteria, fungi ,all of them) 9- lamprey use its………… to rasp away the fish flesh so it can feed on its host’s blood and body fluid..(fore limps ,Hindlimps ,tongue ,non of them ) 10 – the relation between anemone fish and sea anemones. (mutualism ,parasitism ,commensalism, all of them ) 11- sea otters whose numbers were once estimated between…….. Were hunted..(100,000: 200,000 ,20,0000 : 30,000) 12- …………. occurs between members of different species.. ( intraspecific competition, interspecific competation ,predation ) 13 - lives in body of the host..(predator, competitor, parasite,non of them ) 14_ the relationship between nitrogen _fixing bacteria and leguminous is ……….. (predation, competition, parasitism ,mutualism) True or false 1)One species benefits and one unaffected called mutualism. 2)https://www.britannica.com/science/parasitism competation is relationship between two species ,one benefits and other unaffected. 3)3-intraspecific competition occurs between members of different species. 4) Southern sea otter prey mostly on marine vertebrates. 5) sea otter depend on thic fur to keep warm. 6)sea urchin is keystone species control sea otter. 7)Resource partitioning help in competition between two species. 8) kelp are Yellow algae that live in cool ,relatively shallow water close to shore. 9)lamprey uses its tongue to rasp the fish flesh ,so it can feed on host’s blood. 10)the relation between leguminous plant and bacteria is competation. Resources 1. https://academic- accelerator.com/encyclopedia/sea-otter 2. Knight TM, Chase JM, Goss CW, Knight JJ. 2004 Effects of interspecific competition, predation, and their interaction on survival and development time of immature Anopheles quadrimaculatus. J. Vector Ecol. 29, 277-284. PubMed, ISI, Google Scholar 3. https://www.cambridge.org/core/journals/envi ronmental-conservation/article/abs/kelp- forest-ecosystems-biodiversity-stability- resilience-and- future/105EB05670376912F180E116D64135D6 4. https://www.britannica.com/science/parasitism 5. https://www.biologyonline.com/dictionary/mut ualism 6. https://dictionary.cambridge.org/dictionary/en glish/commensalism