Materials and Methods: To gather the needed data on the crayfish, samples were collected at Pearson’s Creek, a little outside Springfield. The spring was right off the road and located directly next to a little over pass. Sampling occurred early morning 0830-0930 on a cloudy day. The weather was a typical mild late summer morning with a rain shower that had passed through the evening before. Two sampling areas that were 10-meters long and the width of the stream were marked off using flags and sticking them in the rocks of the shallow area of the creek. The sample areas were also marked at the 5-meter mark to split each individual trial into two to have a greater chance at collecting a larger population size. The two sampling sites …show more content…
The removal method was done in the 10-meter section that was more upstream and capture-mark-recapture was done more downstream. The purpose of the removal method is to collect a sample of the crayfish and set it aside, away from anymore collections. The next capture should have relatively less than the first. This process is repeated until five trials are finished and each trial having less sample size than the previous one (Zippin 1958). The next method, capture-mark-recapture, is done by catching a sample in a bucket and recording the amount of crayfish and then releasing the samples back into the collection area once marked; in the specific experiment blue and pink nail polish were the marks used (Pradel 1996). In each method, two students stood holding a weighted-down net at the five-meters mark while five other students started at the beginning and shuffled, kicking up rocks to disturb the crayfish underneath. Once the shufflers reached the net, the net was taken out of the water and any crayfish collected were attached to the net. The samples were put into buckets after their length (head to beginning of tail) were measured using a measuring tape and the amount of crayfish were accounted for. The same process was repeated but the net was at the 10-meter mark and the students started shuffling at the five-meter mark. In the capture-mark-recapture method, the crayfish were marked using blue and pink nail polish allowing for the crayfish to be dumped back into the sampling area. The removal method group kept all of the crayfish collected aside to ensure only the new crayfish were collected. The 10-meter portion of the stream was then collected four more times, giving a total of five separate collections for each
During the 1990’s it was discovered that a decline in the population of Red Knots occurred, simultaneously with the decline of horseshoe crab eggs. It was hypothesized that this event was significant and was the cause of the waning population of Red Knots. The Red Knots main dietary staple is horseshoe crab eggs and the nutrition provided
Blackfish, a documentary by Gabriela Cowperthwaite, a historically observed impact of the captivity of killer whales. This Documentary focuses on the orca Tilikum, who was captured off the coast of Iceland. On February 21, 1991, Sealand trainer Keltie Byrne fell into the pool with Tilikum. She was pulled to the bottom by Tilikum, tossed around, and drowned. It took Sealand employees two hours to recover her.
Students started off with a population of ten Skittlefish (skittles) on an orange reef (construction paper). The skittles had varying colors, and the adaptive trait being examined was the ability to blend in with the reef so the predators would not find them. The hypothesis that was thought up was that individuals’ survival was based on their location and coloring. The first year began with two of each color, and 5 Skittlefish were eaten that “year”. The ones eaten were two green, two purple, and one red.
The nets at the mouth of the river collected a “record of 352 adult walleye were captured surpassing the old record of 320 captured in 2004” (Lemon). “According to the Division of Fish and Wildlife website,
Before getting the goldfish subjects, two beakers were filled with 200 ml fish water and weighed. Four goldfish were then collected gently from the fish tank and each two of them were transferred into one beaker. Each beaker along with fish and water was weighed again to determine the weight of each pair of goldfish. For the control group of each trial, the oxygen chamber was firstly filled with 200 ml fish water; after two goldfish along with 200 ml water were transferred into it, it was sealed in order to prevent oxygen exchange with the ambient environment.
Crab pots or traps which are designed to only capture the target crab of legal-sized, Crab pots and traps are generally designed to target a particular species, which means that under-size crabs and accidental capture is usually rare. Moreover, as the pots or traps do not injure the captured animals, it is easy to release any unwanted species or undersized crabs. Because crab pots and traps sit stationary on the seafloor in one location, they do not cause significant habitat
km-2) and ED was tested by calculating correlation coefficients (rs). ED was estimated from grab samples taken at the midpoint of each crab trawl track. The correlation between crab abundance and distance from CSA to the midpoint of trawl track was also tested. Finally, distance from CSA was divided into 2 km bins (0 - 2, 2 - 4, 4 - 6, and > 6 km) to investigate whether RKC abundance changed non-monotonically with distance, and the Kruskal-Wallis test was used to examine whether RKC abundance differed between bins. Stomach evacuation model
Also, there was different categories of critters in the water. There are 846 critters in group 1, 288 critters in group 2, 466 critters in group 3. Due to the experiment of the water velocity, we found out that the velocity is random at each point. This is good, because it means that the dissolved oxygen levels are to be high. The crayfish, belonging to the crustacean group is plentiful in the creek.
Your response: I learned that certain unusual animals can reproduce on their own. If a zebra shark can reproduce without a male then other animals can do the same. Sharks laying eggs without a male isn’t unusual. Leonie was with a male shark at first before she started reproducing on her own. Zebra sharks can lay several eggs throughout their lives even if the male is present.
Describe or sketch different methods you might use to shuck and oyster: ⦁ Answer:
It is strongly recommended to avoid those activation to protect stream environment for eel natural habitat.(17) Thus, in light of the results in this study, it can be assumed that excavation and habitat destruction observed in recent years has probably reduced the quantity and quality of suitable habitats for juvenile eel, which could be negatively affecting both ecologically and economically. 4.5 Further studies Various observations European eel life history should be describe not as truly catadromous, but "facultative or semi catadromous". Due to fact that European eel were found in different waters such as freshwater,brakish and coastal,and freshwater phase is not be a essential part of their life history, could not make them not truly catadromous species.(18) This is the only experimental study until now, as far as we know, that contribute to the understanding the habitat choice of eel juveniles in brackish salinity water .Therefore
Horseshoe crabs are marine living fossils, probably traced back to 485 million years ago. There are two horseshoe crab species found in Hong Kong. Horseshoe crabs are an ancient marine chelicerates, identified as the Class Merostomata, Order Xiphosura. The animals are identified by the possession of appendages around their ventral mouth and their swimming legs at their distal end.
and I could pick up these steaks. This is not so with crawfish. The availability and ease to access live crawfish is very limited, especially in an area such as mine that is surrounded by crawfish ponds. Unless you know someone, such as a farmer, to buy live crawfish on a random basis is very
Stocking is another alternative to the fish ladder. However, it was expensive and inefficient compared to fish passes technique. According to Agostinho et al. (2010), stocking is a method of managing fish populations which by releasing of cultivated or wild organisms to replenish a specific stock in order to increase the fishing yield by the natural recruitment. There are two divisions of stocking, that are maintenance stocking and the supplementation stocking.
In fact, none of my club members ever caught a crucian carp in a river. Today we usually go hunting for crucian carp in the archipelago of Stockholm or lakes that we know contain large specimens. We haven’t found any answers to the question of why the crucian carp is large in some lakes and small in others. The only piece of good advice I can give is to talk to local anglers. They normally know in which lake you can locate large crucian carps even if they don’t fish for them.