User:Mollyskinker/Eurhamphaeidae

Eurhamphaeidae
Eurhamphaeidae are gelatinous predators that belong to the order Lobata within the Tentaculata class of the Ctenophora.

Taxonomy
The family Eurhamphaeidae contains three genera:


 * Genus Deiopea
 * Genus Eurhamphaea
 * Genus Kiyohimea

Basic Morphology
As part of the phylum Cteneophora, Eurhamphaeidae are gelatinous predators have the defining characteristics of rows of fused ciliated plates, combs, used for swimming as well as having colloblasts used for prey capture. Ctenophores are known as "comb jellies" after the eight rows of ciliary plates. The two tissues layers, endodermis and ectodermis, are separated by a gelatinous layer known as the mesoglea. Species within this phylum posses an apical sense organ which contains a calcareous statolith that aids in orientation. Eurhamphaeidae can be further characterized by the Lobata specific characteristics. Such morphology includes broad lobes that grow out or near the oral end with a row of tentacles located around the mouth. Ctenophora organisms are found in oceans of all depths and regions. They can be both planktonic and benthic and regularly found in pelagic zones. Eurhamphaeidae and other gelatinous marine organisms are hard to study outside of in suit observations because they can not be captured in nets due to gelatinous body state. Many species of Eurhamphaeidae are therefore observed in their natural environment using submersibles.

Bioluminescence
Another key feature of animals within the phylum Ctenophora is bioluminescence. The capability of bioluminescence stems from the cells within the comb plates. When activated, the combs produce light. Ctenophores can use bioluminescence for many different purposes including prey attraction, mate location, to startle predators, or predator evasion. Bioluminescence varies in intensity and color among marine species as the ability to produce light is heavily dependent on the conditions of the organism. The effect of difference in organism conditions on bioluminescence is seen in Eurhamphaea vexilligera. The species Eurhamphaea vexilligera uses bioluminescence in a special way. When the animal is disturbed a luminous cloud is secreted. This is unique to the species as bioluminescence in Cteneophores if often observed through combs that reflect light when they move.

Auricles
Eurhamphaeidae have cilia on structures called auricles. These structures are located between the lobes opposite of the mouth. These structures are used for two purposes. The first is to produce currents. The movement of the auricles moves fluid toward the body. These currents aid in the second purpose of the structure: prey capture. The current produced moves water toward the body and mouth of Eurhamphaeidae resulting in prey being drawn toward the mouth and captured when it comes into contact with the lobes or oral tentacles. The presence of auricles allows for species in the order Lobata, like Eurhamphaeidae to generate currents aiding in movement and prey capture.

Reproduction and Development
Reproduction systems and activities in ctenophores is not well understood. While the processes of reproduction in Eurhamphaediae is unknown, reproduction in the sea walnut (Mnemiopsis leidyi) ,a species in another family of Lobata, is more understood. Ctenophore species are often simultaneous hermaphrodites and some species are able to self-fertilize (ex: the sea walnut). Individual organisms produce eggs and sperm in their gonads. The eggs and sperm are released into the water for fertilization or are self-fertilized within the individual. Once the embryos are fertilized, they grow rapidly into cydippid larvae and then into adults. Ctenophores experience direct development between the larval stage and adult form.