Pecten gibbus (Linnaeus, 1758)

Biological evolution is supported by the fossil record because it shows through observable facts how animals are related, their similarities and differences to one another, and how they change over time. Natural selection is a mechanism for biological change because those that want to survive will find a way by changing, passing that change on to it's babies. Whatever doesn't change dies out. Certain traits quit appearing because they didn't work in the environment and the animal died. This is similar to checmical evolution. There were basic models of life before bacteria, possbily a virus. That virus changed to create the first bacteria. As the bacteria spread, adaptions were passed on creating a more complicated living thing. Theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record, because scientists can see certain traits that stopped showing and how some traits appeared allowing that species to continue to exist. Scientific theories on evolution and the fossil record change over time because new animals are discovered, or studies more closely, adding to current theories or changing them, like the pecten gibbus being related to things originally not suspected.

Physical Characteristics

Related Organisms

• Equal and deep valves
• Radiating ribs
• Creamy white to yellowish color
• Marked with patches of bright red, maroon, or lavender
• "The left valve typically more brightly colored than the right" (Hill).
• Hinged wings
• Up to 2" in shell height & and over 3" in shell length.

Historical and present relatives include mullusks, snails, slugs, and other gastropods, clams and other bivalves

Misidentified Species

Two other scallops that look similar are the bay scallop, Argopecten irradians, and the rough scallop, Aequipecten muscosus. The difference is that the first is usually solid gray or gray/brown and the second has unequal wings.

Synonym of Argopecten gibbus

Origin and Evolutionary Life of Pecten gibbus

Hill, K. "Indian Lagoon Species Inventory." Smithsonian Marine Station at Fort Pierce, edited by K. Hill, Smithsonian Marine Station, 16 Mar. 2005, naturalhistory2.si.edu/smsfp/irlspec/ Argope_gibbus.htm.

Serb, Jeanne. "Developments in Aquaculture and Fisheries." Science Direct, vol. 40, 2016, pp. 1-29. Science Direct, doi:10.1016/B978-0-444-62710-0.00001-8. Accessed 9 June 2020. Abstract.

Time Period

From the Cretaceous period to the Quaternary period. They range from 70.6 to 0.0 million years old.

Behavioral Characteristics

Biological Evolution and Phylogeny

Locations

• very diverse
• scientists thought they had clear lines of relation and connections but found suprise connections with other species
• thickness of shells changing over time

Coastal salt waters - Maryland through Florida, the Gulf of Mexico, and south to Brazil, including Bermuda and much of the Caribbean.

Swims actively, especially to avoid predators, horizontally using its valves to propel itself on jets of water.

Feeds on microalgae, diatoms, bacteria, washed over the gills and sent to the mouth.

Serb, Jeanne

Kingdom: Animalia

Phylum: Mollusca

Class: Bivalvia

Order: Pectinida

Family: Pectinidae

Genus: Argopecten

Species: A. gibbus

Binomial name

Argopecten gibbus

(Linnaeus, 1767)