Overview of White Sturgeons as a fish

White sturgeons are species of the Acipenseridae whose habitat ranges from central California and Aleutian Islands . This type of fish are employed by humans for food and are either endangered or threatened. However, today, there are considerable measures and approaches aimed toward conserving whiter sturgeons. within the field of agriculture, farmers are rearing fish either for consumption or commercial purposes. In other words, sturgeon has become increasing important for aquaculture operations in Japan, Eastern Europe, Russian and Iran thanks to the decreasing natural sources. Aquaculture of the fish results in faster and increased growth also as simple productivity. Also, the approach is tolerant to variable rearing conditions. Conversely, there are significant factors that influence productivity of the aquaculture operation: temperature, size of the fish and feeding rate (Peterson, Paul and Cecil 57). Therefore, it is imperative to identify optimum feeding rate which offer maximum growth ratio. More importantly, in the healthy diet consists of a mixture of protein for growth, mineral salt, fats for energy, carbohydrate and vitamins. Growth of fish requires balance of these components in the correct proportion based on the size or energy demand of fish. The approach gives the body the ability to growth at sustainable rate. At the same time, it prevents illnesses and mortality. However, differences scholars have indicated that the primary challenge arise from under and overfeeding (Peterson, Paul and Cecil 57). Too much nutrients result to overnutrition, overdosing, deterioration of quality of water, fish mortality and reduction in feeding as well as production capacity. However, the specific sturgeon life history traits of the different species including the long inter-spawning and late maturation contributes to their vulnerability disturbances due to the above mentioned elements encompassing quality of water (Peterson, Paul and Cecil 57). Therefore, there is a need to determine the optimal feeding rate as well as frequency to oversee success of aquaculture system. Additionally, the economics of the feed is fundamental as farmers should comprehend conversion of the feed to obtain the correct ratios. Feed conversion and growth are considerable components that determine the economic viability of species for restoration and large-scale production of sturgeons. Conversely, literature illustrates that classic composition and feed current mixing methods are not reliable elements for identification of suitable rate for the surgeon, particularly, because of differences in metabolic rate and efficiency (Peterson, Paul and Cecil 57). At the same time, cost is another considerable factor because of great operating expense in the aquaculture activity. Recent research studies conquer that it is critical to optimize feeding techniques to increase maximum fish growth and minimal size heterogeneity. These strategies can lead to reduced cost of production and result in rapid and easy growth of the fish. However, it is imperative to note that although there are considerable investigations conducted to identify the importance of feeding rates, there is little information on feed requirements, especially, when it comes to the various species of sturgeon. The available data is mostly related to the Siberian sturgeon with several research endeavors have been reported regarding growth performance. Further, there is some is research on the feeding rate of Persian Sturgeon. However, there is still a considerable gap to studies and understanding the yearling white sturgeon. Therefore, the primary aim of the paper is to carry out a literature review on this type of fish. In particular, the report focuses on sturgeons' biology in general, historic fisheries record, current status and distribution first. The next segment will look at effect of feeding rate on growth response in fish in general, sturgeons and finally more specifically to the white sturgeons.
Sturgeon general biology, Historic Fisheries, Distribution and Current Trend
Sturgeon General Biology
Peterson, Vecsei, and Jennings (2017) focus on the general biology of sturgeons by describing the organisms' morphology and life cycle. According to the author, there are about 23 species of sturgeons mostly found in freshwater rivers and lakes. However, some travel and return to rivers for breeding. Sturgeons can grow to as large as 4.2 meters and have rows of large, bony scutes on their bodies. Further, they have ventrally position mouth and four barbels. The most noticeable feature is the scales body that is protected lateral rows of bony plates. Usually, their bodies appear to spindle-shaped with anal fin located posterior of the dorsal part. They have bony plates that cover the head and five longitudinal rows of similar scutes along the body (Peterson, Vecsei and Jennings 341). Their tail fins are heterocercal with the upper lobe being longer than the lower one. Additionally, they do not possess any teeth, and the underside of the snout is preceded by four sensitive tactile barbells that drag the fish to the bottom of the water in search for small invertebrates for food. Acipenser has small, numerous roe or sticky eggs and when they hatch the young grow rapidly to maturity after which the growth continues gradually for several years. A single female can produce between 100,000 to 3,000,000 eggs, but not all are fertilized. However, those that are become sticky and adhere to a contact (Peterson, Vecsei and Jennings 341). Commonly, it takes between 8 and 15 days for the embryo to mature into larval fish. During that period, they depend on the yolk sac for nourishment (Peterson, Vecsei and Jennings 341). Similarly, the source provides details of the life cycle of sturgeons and contends that their average lifespan is approximately 50 to 60 years. Their first spawn does not take place until when they are between 15 and 20 years old (Peterson, Vecsei and Jennings 341). They are broadcast spawners but do not necessarily spawn each year since they require certain conditions. The requirement may not be met because of varying weather conditions such as photoperiod in spring, water temperature and flow of oxygen. At the same time, sturgeons reach between 18 and 20cm in their first year if growth.
Historic Fisheries, Distribution and Current Trend
LeBreton, Beamish, and McKinley (2016) outline the historic fisheries and distribution of sturgeons in the North American. According to the author, the largest commercial sturgeon fisheries are in Iran, Ukraine and Southern Russia though fishing is also carried out in Europe and United States. According to the source, 1960s saw historic sturgeon fishing in North America as the animals were exploited to near extinction. In the 1800s, over 60,000 pounds were harvested from Lake Michigan and by 1910 only zero sturgeons were caught from region because there were few left (LeBreton, Beamish and McKinley 428). In particular, the sturgeons become threatened because of their swim bladder (use for development of industrial products, for example, isinglass gelatin), eggs and flesh. The authors report that since 1990s there has been 78% decrease in Russian, Beluga and Stellate sturgeons with numbers in the Caspian Sea declining from 142 million to 43.5 million which represent 79% decrease (LeBreton, Beamish and McKinley 428). The scholars assert that the issue has been exacerbated by poor management of the Caspian fisheries. At the same time, although there are no species that have gone extinct, a considerable number of subspecies have been wiped out in Caspian fisheries. Similarly, the author focuses on the sturgeon fisheries in the Middle Danube from and contend that the place remains the largest historical site that indicates the role of sturgeons in prehistoric nutrition in Roman and middle ages.
Further, sturgeons are majorly found in the northern hemisphere and range from subtropical to subarctic waters in Eurasia to North America: Gulf of Mexico, Newfoundland, Missouri, Great Lakes, and Mississippi Rivers. They are also found in the European Atlantic coast including the Adriatic Sea, Mediterranean basin, and rivers situated in Italy. In the Pacific Ocean, sturgeons are found in Amur River along the Chinese-Russian board. Regarding the current status of the fish, the article shows that there has been considerable measure out forward by government and different agencies to protect the existence of the sturgeons across the world. There legal approach according put forward according to the current status of the species in Europe, America, China, and Russia. Since the establishment of sturgeon conservation methods, there has been the significant propagation of a number of the distinct species across the globe (LeBreton, Beamish and McKinley 428). However, in the north Pacific Coast, population of white sturgeon has been declining since 1960s. The problem has been contributed by lack of recruitment of breeding juveniles since 1974. The decrease corresponds to the opening of the Libby Dam in Montana resulting in poor quality of water of rivers such as Kootenai. Also, the authors show that the white sturgeon population has been decreasing from 1960s to 2000s and has led to loss of about 700, 000 sturgeons in North Pacific Coast area (LeBreton, Beamish and McKinley 431). Conversely, a joint effort between United States and Canada are underway to address the issue through the development of recovery strategy. The current trend shows that ten juvenile sturgeons are produced in the region.

Effect of Feeding Rate on Fish Response
Effect of feeding Rate on fish Response in General
According to Cui, Yibo, and Silas SO Hung (1996), good nutrition is important for production of health and high-quality fish. Feeding rate is crucial nutritional determinant because it represents 40-50% reduction in costs (Cui, Yibo, and Silas 26). Also, the method is fundamental for increasing productivity since small fish and fries need to be fed high protein diet because of their high energy demand. As such, they are required to eat almost all the time. However, overfeeding has been demonstrated to be a great challenge because young fish need a little amount of feed relative to their volume of water in the aquaculture system. Therefore, feeding frequencies and rates must be identified to obtain the best level of production at low cost. More important, the determining feed rate is critical because nutritional intake of fish is affected by season, time of the day, and temperature of water as well degree of oxygen (Cui, Yibo, and Silas 26). For instance, Peterson, Vecsei, and Jennings (2017) hold that it is not advisable to feed the fish in the morning because reduced dissolution of oxygen characterizes the period. On the contrary, feeding can constantly be performed when there is recirculation of oxygen. Conversely, the feeding rate declines during winter and when water temperature is significantly low which means feeding the fish should be decreased proportionately. Therefore, fish farmers are advised to pay careful attention to the feeding activity to determine feed conversion ratio, feed acceptance, and efficiency as well as monitor cost.
Effect and Importance of Feeding Rate in Sturgeons
According to Deng, Koshio, Yokoyama, Bai, Shao, Cui and Hung (2003), feeding rate is important because it determines the performance of sturgeons. In particular, the obtaining feed rate is critical because the approach takes into account the factors such as temperature and fish size. Therefore, identification of the feeding rate is fundamental to the success of any aquaculture operation (Deng et al. 590). In particular, the issue is crucial for sturgeon larval fish because they are commonly susceptible to under and overfeeding which increases incidents of sickness and death. Therefore, feeding rate helps in determination of the growth performance of sturgeons. The information is affirmed by Lee, Wang, Hung, Strathe, Fangue and Fadel (2014) who assert that feeding cost is considerable factors that impact the bottom line of aquaculture activities. Feed utilization and growth are part of the primary aspects that influence the growth of sturgeons. The elements are affected by the rate of feeding of the fish. However, overfeeding can lead to poor quality of water and jeopardy of health and survival of the organisms. As such, identification of the optimum feeding rate is critical for maximum production and ensuring reduced feed loss as the first step toward achieving successful aquaculture of fish species (Lee et al. 297). Consequently, feeding rate impacts the efficiency of aquaculture operations and productivity since the small larval fish and fry need to be feed optimal diet frequently based on their high energy demands. Understanding the feeding rate of sturgeon allows 40% to 50% reduction in production costs (Lee et al. 297).
Effects of Feeding Rate on Growth Response of White Sturgeon
Growth Trials that were done on white Sturgeon
Hung, Silas SO, and Paul Lutes (1987) performed a study to that focused on understanding feeding rate of Acipenser transmontanus to increase the commercial fish production. According to the article, information on the optimum feeding rate is important because it provides the largest growth per unit (p.450). The finding of the study indicates that feed efficiency of juvenile sturgeon at 20oC, 23oC, and 26oC was between 131-129%, 131-122%, and 114-86% respectively (Hung, Silas, and Paul 46). The figures demonstrate that feeding rate enables a culturist to ensure sustenance of good water quality maximizes efficiency of production and reduce environmental stress. The objective of the research was to determine the optimum rate of white sturgeon yearlings in commercial production situation (Hung, Silas, and Paul 46). The results show that dissolved oxygen and temperature are the two most critical environmental factors to be considered to boost feed efficiency in a fish production system. Furthermore, the article illustrates that oxygen injection into the water can have a significant impact on the growth of the fish and feeding efficiency of the white sturgeons.
Lee, Haller, Fangue, Fadel, and Hung (2016) also conducted a study to identify the performance rate of white sturgeons. The trial was carried out to assess the impact of feeding rate on nutrient portioning and growth as well as the determination of the optimum rate for the young-of-the-year white sturgeons. Three tanks were used and assigned thirty fish each. They were subjected to five feeding rates each day. The weight of the fish was taken. According to the authors, increased feeding rate impacts the whole-body mass and moisture. The finding illustrates that optimal feeding rate is important for the growth of white sturgeons (Lee et al., 211). Such determination is critical for the success of aquaculture activities or commercial production of fish.
Similarly, De Riu, Zheng, Lee, Lee, Bai, Moniello and Hung (2011) performed a trial to determine the impact of feeding rate on white sturgeon growth performance fries. The researchers fed the fish six times a day. The fries were kept at between 18 and 19oC and were fed commercial Salmond (De Riu et al.1). The study result showed increased body weight, specific growth rate patterns, and efficiency. According to the researchers, lipid and body moisture were considerably impacted by the feeding rate. However, the study demonstrated that rate of feeding did not influence body proteins. Consequently, the scholars were able to calculate the optimal feeding rate for the fries (De Riu et al.1). Therefore, the result reveals that feed efficiency and growth rate are critical factors that determine the viability of commercial aquaculture project. The challenge can be overcome by identifying the optimal feeding rate for the white sturgeon species under consideration.
Hung and Lutes (1987) did an experiment identify the optimal feeding rate for hatchery of white Sturgeon. The study was performed at 20oC and the sturgeons were given purified diet ranging from 0.5% and 4.0% for eight weeks. The research showed that whole body moisture, weight, and feeding rate were considerable impacted. However, the body proteins did not change significantly which suggested the need for reduced feeding rate for this nutrient. Additionally, the scholars realized that feed gain ratio and body weight increase for the hatchery of white sturgeon was 2.0% (Hung and Lutes 187). More importantly, the authors demonstrated that age, shape of the fishing tank, temperature of water, supply placement, and stocking density of the feed. Therefore, the article contends that the above factors influence the feeding rate and should be taken into account to determine the most appropriate or optimal rate to increase growth performance of the hatchery. On the other hand, Hung, Lutes, Shqueir, and Conte (1993) affirms that water temperature, and feeding rate and fish sizes are the most fundamental factors that determine the growth of white sturgeon. Primarily, the authors aim at understanding how water temperature impacts the feeding rate. The fish were reared at 23oC to 27 oC (Hung et al. 173). The finding indicates body weight increase after increasing temperature. The results were attributed to increasing feeding rate of white sturgeons.
Growth Trials that have been done on Other Species of Sturgeon
Zheng, Deng, De Riu, Moniello and Hung (2015) performed a four-week trial study on green sturgeon fry to identify the impact of rate of feeding on their growth performance (Zheng et al. 219). The experience was carried out at 18oC and fed salmon containing between 2245 and 457 crude protein and 201 and 207 lipids (Zheng et al. 219). The author noticed an increase in body weight feeding efficiency and whole body moisture as well as energy content. The optimal feeding rate determined included 7.1, 5.7 and 5.3% for trial I, II, and IV (Zheng et al. 219). The researchers demonstrated that optimal feeding rate influences maximum growth rate of the green sturgeon fries.
Conclusion, objective of the study and hypothesis
Current body if literature identifies several factors that influence the feeding rate of the fish. Aquaculture is being used in different parts of the world such as Japan, Europe, and Russia as mean of restoring the sturgeon species and for large-scale production of the fish. However, the process can be economically and productively challenging because of environmental factors that affect the feeding rate. More importantly, distinct writers have noted that it is important to have balanced diet for the fish to maximize production. A healthy diet consists of a mixture of protein for growth, mineral salt, and fats for energy, carbohydrate as well as vitamins. The growth of fish requires a balance of these components in the correct proportion based on the size or energy demand of fish. Therefore, there is a need to determine the optimal feeding rate as well as the frequency to oversee the success of aquaculture system. A vast number of studies agree that it is imperative to optimize feeding taking into account the environmental conditions and feed conversion ratios to reduce the cost of the product while at the same time maximizing the growth of the fish. However, most of the research studies have focused on the Siberian sturgeons and how temperature, water quality, light intensity and size of the fish impact feeding rate. Little attention has been given to the white sturgeon, especially, when it comes to the performance of the feeding rate and conversion. Therefore, the primary objective of the study is to examine the feed conversion and growth performance for white sturgeons at different feeding frequencies and rates.
The following is the primary hypothesis of the research:
H0: Feed conversion and growth performance is affected by the different frequencies and rates.
H1: Feed conversion and growth performance is affected by the different frequencies and rates.

Works Cited
Cui, Yibo, and Silas SO Hung. "A prototype feeding-growth table for white sturgeon." Journal of Applied Aquaculture 5.4 (1996): 25-34.
De Riu, et al. "Effects of feeding rate on growth performance of white sturgeon (Acipenser transmontanus) larvae." Aquaculture 217.1 (2003): 589-598.
Deng, Dong-Fang, et al. "Effects of feeding rate on growth performance of white sturgeon (Acipenser transmontanus) larvae." Aquaculture 217.1 (2003): 589-598.
Hung, Silas SO, and Paul B. Lutes. "Optimum feeding rate of hatchery-produced juvenile white sturgeon (Acipenser transmontanus): at 20 C." Aquaculture 65.3-4 (1987): 307-317.
Hung, Silas SO, et al. "Effect of feeding rate and water temperature on growth of juvenile white sturgeon (Acipenser transmontanus)." Aquaculture 115.3-4 (1993): 297-303.
Hung, Silas SO, et al. "Growth and feed efficiency of white sturgeon (Acipenser transmontanus) sub-yearlings at different feeding rates." Aquaculture 80.1-2 (1989): 147-153.
Hung, Silas SO, Fred S. Conte, and Paul B. Lutes. "Optimum feeding rate of white sturgeon, Acipenser transmontanus, yearlings under commercial production conditions." Journal of Applied Aquaculture 5.1 (1995): 45-51.
LeBreton, Greg TO, F. William H. Beamish, and Scott R. McKinley, eds. Sturgeons and paddlefish of North America. Vol. 27. Springer Science & Business Media, 2006.
Lee, S., et al. "Effects of feeding rate on growth performance and nutrient partitioning of young‐of‐the‐year white sturgeon (Acipenser transmontanus)." Aquaculture Nutrition 22.2 (2016): 400-409.
Lee, Seunghyung, et al. "Development of optimum feeding rate model for white sturgeon (Acipenser transmontanus)." Aquaculture 433 (2014): 411-420.
Peterson, Douglas L., Paul Vecsei, and Cecil A. Jennings. "Ecology and biology of the lake sturgeon: a synthesis of current knowledge of a threatened North American Acipenseridae." Reviews in Fish Biology and Fisheries 17.1 (2017): 59-76.
Zheng, K. K., et al. "The effect of feeding rate on the growth performance of green sturgeon (Acipenser medirostris) fry." Aquaculture Nutrition 21.4 (2015): 489-495.