Taking a Look at Horseshoe Crabs

In this essay i’m going to tell you about the fiddler crab. Here is one fact the fiddler

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

Horseshoe crabs are an important part of the wetland ecosystem, however they are going extinct. Due to harvesting, pollution, and other animals consuming their offspring their numbers are dwindling. They play an important part in the ecosystem and need to be protected so they do not become extinct. The Delaware bay has decided to protect them for their future uses in medicine and to keep them as an important role in the ecosystem.

The argument the author puts forth is that horseshoe crabs have evolved over the eras. That they’re not “living fossils”. Horseshoe crabs have “rounded cephalic shields, that were like the extinct trilobites, and an arrangement of legs and gills”, no wonder people think they are living fossils. This is the beginning to how these historic animals have evolved.

The Purple Marsh Crab, or simply known as the Marsh Crab, is a small crab that is native to the Eastern United States. They live in the salt marshes and mud flats of brackish estuaries, and create networks of connected tunnels within the flats.

The Mantis Shrimp is a mid sized crustacean that can grow up to 3 to 18 centimeters in size. It is known for its bright colors of blues reds and greens, they are primarily green on the belly it has bright reds and oranges on its legs and spots on its framework, while a bright blue is on its eyes. Females are almost always more orange and red than males which are in more various colors. Their spears or clubs are what define this species, these clubs are what mantis shrimp use as a deadly weapon, they can accelerate these clubs at the speed of a bullet from a .22 caliber rifle. Their eyes can see 12 different color waves the most of any animal discovered on earth. They make their homes by burrowing into the ground or finding old burrows left

On this image, we see the external dorsal side of a preserved crayfish. As part of the largest animal phylum the Arthropoda, the body of the crayfish is segmented, with jointed appendages and exoskeleton. The paired antennae (1) are long appendages located the front of the mouth and modified for help the animal to sense touch and taste. The antennules (2) are shorter, also paired with the same function but they also help to maintain balance. The chelipeds (3) are located on the front of the thorax, and they are responsible for defence and grasping food. On the at ventral part of the thorax, we found four pairs of walking legs (4), with these legs the crayfish changes locations on the bottom of freshwater lakes, streams and also on land. They

The horseshoe crab and the trilobite do share a common ancestor. There are many pieces of evidence in the anatomy of both species that support this claim. A first piece of evidence is that both species have an outer exoskeleton but no internal skeleton. This separates both of them from vertebrates, making both of them invertebrates. The second piece of evidence supporting walking legs of both species are also positioned on the underside of the animal, protected under the shell. Both the trilobite and the horseshoe crab have one horseshoe-shaped cephalothorax with a raised ridge in the middle of it and two eyes positioned on either side of the ridge. The mouth of both species is on the underside of the body as well, unlike crustaceans and insects

The blue crab Callinectes sapidus is a wide-ranging, ecologically and economically important species along the Atlantic and Gulf of Mexico (GMx) coasts of North America. Consequently, its basic biology, life history, population genetics, and demography have been the subjects of numerous studies. For my dissertation research, I propose to focus on two critical areas concerning the ecology and evolution of blue crabs that have broader implications for our understanding of marine organisms with biphasic life cycles. For the first chapter I will investigate the unusual finding of extreme temporal and spatial variation in the genetic composition of settling blue crab larvae along the Texas coast. Since it was reported in 1993, this finding been

Every hermit crab changes shells eventually because, their old shell could get too small or they just feel like trying something new. Once a crab finds a new shell, it then

The Palaemonetes vulgaris were brought back to the lab in buckets. Then the Palaemonetes vulgaris were measured for their length. Calipers were used to measure from the tip of the rostrum to the end of the telson for the total body length to the nearest 0.1 mm. On that same specimen, for the carapace length, calipers were used to measure from the tip of the rostrum to the end of the carapace to the nearest 0.1 mm. Then the specimens were placed into a discard bucket so they weren’t measured twice. The Palaemonetes vulgaris are released back into their native home after all needed measurements were recorded. The recorded measurements of twenty-five Palaemonetes vulgaris were placed into a Excel spreadsheet, to calculate the average total length (mm) to be compared with a previously collected dataset from Fort DeSoto.

The American horseshoe crab (Limulus polyphemus) has persisted largely unaltered for millions of years (Smith et al., 2006), and has ancestors that date back 450 million years ago (Swan, 2005). They belong to the genus Limulaceae, and are an ancient group of aquatic merostome arthropods (Sekiguichi, K., and Shuster J., 2011). Limulus polyphemus inhabits the eastern coast of the United States (Goode and Wahle, n.d., Swan, 2005). It ranges from the Yucatan Peninsula to the Gulf of Mexico (Moore and Perkin, 2007 (Shuster, 1979), about 42 to 19° N (Botton, 2003). Limulus polyphemus are found within estuaries, coastal embayments, and on the inshore continental shelves near the mouths of estuaries, usually in waters that are less than 30 meters

“Horseshoe crabs are some of the most successful life forms on earth.” They have been around for over 445 million years. Longer than even the pesky cockroaches. They have a blood that turns to jelly, creating a barrier between them and pathogens, keeping them safe from any diseases. But for the physical harm, they have adapted a hard shell or carapace to protect them from attacks. Horseshoe crabs also have gills as thin as the pages of a book, allowing them to breathe out of water for as long as they are wet. This is especially good for spawning. Speaking of which, they can also produce 90,000 fertile eggs a year, increasing the population. They seem unstoppable.

They are related to crabs and lobsters. They are crustaceans. Isopods live in the sea, or on land. We tested the effect of dark and light on isopods performance. The independent variable is light versus dark.

The taxonomy of Longidoridae has been changing for the last decades. Khan & Ahmad (1975) started to propose the separation of subfamily Longidoroidea from Dorylaimoidea on the basis of long attenuate odontostyle and raising the Xiphinematinae to family alongside with redefining Longidoridae. Luc & Doucet (1984) reviewed the fundamental systematic classification and proposed a simplified scheme only to categorize into Family Longidoridae under super family Dorylaimoidea disregarding the subfamilies due to apparent variation in characters sets among genera. This scheme of Longidoridae classification was accepted by Coomans (1985) but proposed to use the subfamilies Longidorinae and Xiphinematinae. Moreover, Jairajpuri & Ahmad (1992) recognized the Longidoroidea following a slight modification of the scheme and places the Xiphidorinae under Xiphinematidae emphasizing the morphological similarities of Xiphidorus and Xiphinema. Hunt (1993) agreed with the classification of Luc & Doucet, 1984 and Coomans, 1985 in accepting Longidoridae sensu. The concept of subfamily has some value in the group and recognized Longidorinae and Xiphinematinae based largely on distribution, size and shape of pharyngeal gland nuclei and presence or absence of ventromedian copulatory supplements in male. Chavez & Coomans (1984) stated that Xiphinema like characters of odontostyle especially the forked odontostyle base are convincing as it was depicted in some Paralongidorus species exhibiting a solid furcate at base of odontostyle. Delineation among genera uses the diagnostic features such as type of amphidial fovea, morphology of