Featured Invertebrate Data
Although I've only photographed five individuals, the blue seastar Linckia laevigata, is considered to be quite commonly seen by divers, snorkelers, and reef-walkers in Okinawan waters.
Chris Mah has an excellent presentation on Linckia laevigata via The Echinoblog. He lists three things you may not know about L. laevigata. Also general information on starfish is also found on The Echinoblog: How many starfish species are there?? Where do they Live? How long have they been around? Five Points about Sea Star Diversity!
The following description of Linckia laevigata is taken from the Animal Diversity Web (U Mich, Mus. of Zoology):
Linckia laevigata is characterized by five cylindrical arms with a bright blue or light blue body color and yellow tube feet. Green, pink, and yellow colors have also been observed. Individuals can grow up to 30 to 40 centimeters across. These animals get their color from a blue pigment called linckiacyanin and some accessory yellow carotenoids. The starfish colors vary, depending on the exact ratio and combination of pigments in each individual. (Kochzius, et al., 2009; Magsino, et al., 2000; Williams and Benzie, 1993; Yamaguchi, 1977)
Though the sexes appear indistinguishable when observing this animal externally, the differences can be determined by observing the gonads or by examining the act of spawning when the male and female can be distinguished more readily. During the mating process, gametes are released freely into the water above the animals. Seastars gather in groups when they are prepared to mate to increase the probability of fertilization. If a male and female release gametes in close proximity, the eggs are fertilized. Mating generally occurs in the summer. (Yamaguchi, 1977)
Linckia laevigata, like other seastars, are opportunistic predators and scavengers. They invert their stomachs and begin to digest their food externally. Food items include dead animals, small invertebrates, and detritus. (Deep Sea Waters, 2011; Reef Reality Series, 2010)
- Primary Diet: carnivore (eats other marine invertebrates, scavenger); omnivore; detritivore
- Animal Foods: aquatic or marine worms; other marine invertebrates
- Plant Foods: algae
- Other Foods: detritus
The blue coloring of L. laevigata may warn potential predators of toxicity. Like other seastars, the blue seastar can use autonomy, or self-severance of a limb, to escape predation. Body parts lost to predators are regenerated.(Reef Reality Series, 2010; Rideout, 1975)
- Triton shells, Charonia spp.
- Harlequin shrimp, Hymenocera spp.
- Sea anemones
- Damselfish, Dascyllusaruanus spp.
The blue sea star is mainly a scavenger, breaking down tissues of dead animals. Linckia laevigata is an obligate host for the limpet Thyca crystallina, which feeds on the hemolymph of the sea star. The shrimp Periclimenes soror, is also parasitic on L. laevigata. (Crandall, et al., 2008)
As one might guess, because of Linckia laevigata being so commonly seen in the tropical waters of the Indian and Pacific Oceans, there are numerous photos available on-line. One of these on-line sites is Pinterest.
I've added a second page w/ several images of the species.
In addition, I've added a link to the current and past featured invertebrates via a list and thumbnails.