- Insects (from Latin insectum) are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within.
- Star Tales - Hydra (ianridpath.com)
Hydra is the largest of the 88 constellations, winding over a quarter of the way around the sky. Its head is south of the constellation Cancer, the crab, while the tip of its tail lies between Libra, the scales, and Centaurus, the centaur. The total length from its westernmost boundary to the easternmost one is 102°.5. Yet for all its size there is nothing prominent about Hydra. Its only star of note is second-magnitude Alphard, a name that comes from the Arabic al-fard appropriately meaning ‘the solitary one’. Bode on his Uranographia atlas gave it the alternative name Unuk es Schudscha, from the Arabic unuk al-shujā, neck of the serpent. Both names were originally given by al-Ṣūfī in his Book of the Fixed Stars (AD 964).