The Versatile fairy shrimp, scientifically known as Branchinecta lindahli, is a member of the Branchinectidae family. This intriguing species was first documented by Packard in 1883.
The Versatile fairy shrimp is commonly found in temporary habitats, such as dry lake playas, that often contain chemical compounds like calcium sulfate, calcium carbonate, and sodium salts. These environments typically consist of a combination of sand, loam, and clay soils (Rogers, D. C., 2014). Branchinecta lindahli has a wide distribution, spanning from Canada to Mexico. In the U.S., it is predominantly located in the western regions, from the Great Plains to the Pacific coast. This species is usually present in its habitats during the winter or spring months of the year.
Although it is commonly linked to alkaline environments like dry lake playas with moderate to high levels of dissolved solids made up of sodium salts and carbonates, Branchinecta lindahli is not restricted solely to these settings. It is frequently sighted across the western U.S., particularly in states such as California, Arizona, and New Mexico (Thorp, J. H., & Rogers, D. C. 2015).
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's second antenna, positioned close to the body (proximal antennomere), features a small bulge (pulvillus) on the front-middle side near its base, adorned with tiny spine-like structures (spinules) and scales. The antenna's far end (distal antennomere) is flattened and bends inward, marked by two significant bends: one in the middle section and another at the very end, which curves sharply, forming nearly a right angle with the preceding sections. At the tip of this distal end, there is a spatula-like extension that is concave on the underside. The rear edge resembles a rasp, while the upper margin near the tip remains unindented (Obregón-Barboza, Hortencia, et al., 2015).
Female: In females, the second antenna is reduced in comparison to males, and the first antenna is approximately the same length as the second one (Obregón-Barboza, Hortencia, et al., 2015).
Thorax:
Dorsolateral Process (Lobes):
Male: Absent.
Female: The 4th to 9th segments of the thorax, and sometimes the first genital segment, have rounded lobes on both sides that are covered by skin denticles (Obregón-Barboza, Hortencia, et al., 2015).(Lynch, J. E. 1964).
Thoracopods:
Male: limbs are curved with more spines instead of setae
Female: limbs are circular with more fine setae.
Reproductive Segments:
Male: A pair of penises.
Female: The ovaries are biramous, featuring two branches, with the lateral egg duct located at the start of the second genital segment. The amplexial groove, used for mating, is not distinct, and the cylindrical brood pouch lacks specialized structures to accommodate the male's second antennae during copulation. The end of the brood pouch terminates beneath the fourth or fifth abdominal segment, corresponding to the sixth or seventh segments if legless. (Obregón-Barboza, Hortencia, et al., 2015; Lynch, J. E. 1964).
Abdomen:
Abdominal segments possess no unique features and are consistent between sexes.
Telson & Cercopods:
The cercopods, or tail appendages, feature bristles along their inner and lateral margins.
Egg:
The egg, or the closed sac-like structure, has a surface that is decorated with dips (indentations) and raised lines (ridges). It is round in shape and has rib-like structures that form many-sided (polygonal) areas.
Morphology:
Size: The size of this fairy shrimp ranges from 2 cm to 2.5 cm in length, contingent on prevailing environmental conditions.
Coloration: While the body is primarily transparent, subtle tints of colors such as greens and blues might be present.
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: 50 to 72°F.
Temperature Range for Adults: 50 to 72°F.
Hatching: Nauplii emerge within 24 to 72 hours at temperatures ranging from 60 to 72 Fahrenheit.
Growth Rate: This species exhibits a moderate growth rate, achieving sexual maturity within approximately 9 to 13 days. The average lifespan spans 8 to 10 weeks.
Behavior: The versatile fairy shrimp exhibits a swimming pattern that includes vertical movements within the water column. These shrimps mainly partake in filter feeding on microorganisms. When food is scarce, they scrape the substrate from the bottom of their habitat for nourishment. Their movements are graceful, with males showing erratic behavior and females moving smoothly. They typically swim forward continuously, and it is uncommon for them to swim in place.
Reproduction: Males utilize their second antennae to swiftly latch onto females during mating, a process lasting only a few seconds.
References:
Obregón-Barboza, Hortencia, et al. "A Review of the Branchinecta (Branchiopoda: Anostraca) from the Baja California Peninsula: First Record of the Giant Fairy Shrimp B. gigas Lynch, 1937 from Mexico." Journal of Crustacean Biology, vol. 35, no. 3, 2015, pp. 433-440.
Thorp, J. H., & Rogers, D. C. (2015). Thorp and Covich’s Freshwater Invertebrates: Keys to Nearctic Fauna (4th ed.). Elsevie
Rogers, D. C. (2014). Anostracan (Crustacea: Branchiopoda) zoogeography II. Relating distribution to geochemical substrate properties in the USA. Zootaxa, 3856(1), 1-49. Magnolia Press. https://doi.org/10.11646/zootaxa.3856.1.1
Lynch, J. E. (1964). Packard’s and Pearse’s species of Branchinecta: Analysis of a nomenclatural involvement. American Midland Naturalist, 71(2), 466-488. Retrieved from http://www.jstor.org/stable/2423306
Comments