Calveriosoma hystrix explained

Calveriosoma hystrix is a species of sea urchin of the family Echinothuriidae. Their armour is covered with spines. Calveriosoma hystrix was first scientifically described in 1872 by Thomson.^[1] C. hystrix has a structure known as a siphon, which is a thin tube that runs parallel to the stomach. While its function is not certain, it likely serves a way of moving water from the esophagus to the beginning of the intestine.^[2]

Notes and References

1. Kroh, A. (2010). Calveriosoma hystrix (Thomson, 1872). In: Kroh, A. & Mooi, R. (2010) World Echinoidea Database. at the World Register of Marine Species.
2. Holland . Nicholas D. . Ghiselin . Michael T. . 2008 . Siphons and siphonal grooves in the digestive systems of the Echinoidea (Echinodermata) . Zoomorphology . en . 127 . 4 . 259–264 . 10.1007/s00435-008-0071-7 . 0720-213X.