Branchinecta mediospinosa, commonly known as the Kansas fairy shrimp, belongs to the family Branchinectidae. This fairy shrimp closely resembles B. lindahli and shares many similar features. This species is endemic to the state of Kansas, and not much is known about its habitat or preferences. Little information is available regarding the distribution of this species. It was discovered in an artificial temporary pool in Kansas that has since been destroyed.
Anatomy: The characteristics outlined below may exhibit variations influenced by environmental conditions, population dynamics, and the organism's age.
Head:
Second Antenna:
Male: The shrimp has a second antenna that is close to the body (proximal antennomere) with a small swelling (pulvillus) on the front-middle side near the base. This part is covered by tiny spine-like structures (spinules) and scales. On the second antennal proximal antennomere,’ referring to the second segment from the base of the antenna. This segment houses a ‘Medial spiniform tubercle,’ a spike-like bump located in the middle (‘medial’) of the antennomere. Furthermore, the ‘Apically directed’ nature of this tubercle indicates that it points towards the tip (‘apex’) of the antenna. Moving towards the far end (distal antennomere) of the second antenna, it is compressed and curves inward, with two major bends. One bend is in the middle near part, and the other is at the far end, curving very strongly, almost at a right angle to the parts before it. The tip of the far end of the second antenna has a spatula-like projection that is hollow on the lower side. Additionally, the back edge has a surface like a rasp, and the upper border near the end is not depressed.
Female: Reduced second antenna
Thorax:
Dorsolateral Process:
Male: None
Female: None
Thoracopods:
Structure is similar between sexes with spines instead of setae on the edges.
Reproductive Segments:
Male: Pair of penes.
Female: Brood pouch. The females have an elongated egg pouch extending to abdomen segments that points away from the body as it gets closer to the gonopore. The egg pouch can easily hold well over 100 eggs when fully mature.
Cyst:
The cyst is spherical in shape with indentations and ridges ranging in color from tan to white.
Abdomen:
No unique features, same between sexes.
Tail:
Cercopods:
The tail appendages (cercopods) are separate and are set with bristly hairs (setae) along the middle and side borders.
Morphology:
Size: 2.5cm to 2.7cm in length, contingent on prevailing environmental conditions.
Coloration: The coloration is transparent, but they can have blue and brown tints.
Captivity and Growth:
Growth is influenced by multiple factors such as temperature, salinity, and care. These temperature ranges are based on our experience but do not represent the maximum or minimum.
Hatching Temperature Range: 60 to 72°F.
Temperature Range for Adults: 60 to 72°F.
Hatching: At temperatures of 60 to 72 Fahrenheit, nauplii appear after 24 to 72 hours.
Growth Rate: This species has a moderate growth rate, reaching sexual maturity at around 9 to 13 days with an average lifespan of 8 to 10 weeks.
Behavior: This fairy shrimp swims up and down the water column, filter feeding on microorganisms. If there is no food readily available, the fairy shrimp will scrape substrate from the habitat floor to feed on. These fairy shrimp have graceful movements; however, males are more sporadic while females gently glide through the water. They rarely swim stationary but rather always in a forward motion.
Reproduction: Males use their second antenna to latch onto the females, taking only a few seconds to mate.