Images Dated 27th July 2005

Anemone shrimp in its anemone

Anemone shrimp (Periclimenes brevicarpalis) in its host sea anemone (Cryptodendrum adhaesivum). This shrimp has a symbiotic association with the anemone, gaining protection by hiding amongst its stinging tentacles. It is unclear if the anemone gains any benefit through hosting the shrimp, however. This type of symbiosis, where one animal gains and the other is neither helped nor harmed, is known as commensalism. The anemone and its shrimp are found in the tropical Indo-Pacific region

© GEORGETTE DOUWMA/SCIENCE PHOTO LIBRARY

False-colour SEM of secondary oocyte & polar body

Human egg. False-colour scanning electron micrograph of a human egg (primary oocyte) at the end of the first meiotic division, occurring just before ovulation. At this stage the primary oocyte is split into two cells, known as the secondary oocyte (green) and the first polar body (yellow), each containing 23 chromosomes. If after ovulation the secondary oocyte is penetrated by a spermatozoon, it completes the second meiotic division producing a fertilised mature oocyte and one polar body. The first polar body divides into two and all three polar bodies shortly degenerate. Magnification: x700 at 6x7cm size. x1115 at 4x5ins

© PROF. P. MOTTA/DEPT. OF ANATOMY/UNIVERSITY LA SAPIENZA , ROME/SCIENCE PHOTO LIBRARY

Staphylococcus aureus bacteria

False-colour transmission electron micrograph (TEM) of bacteria Staphylococcus aureus, showing a complete bacterium (centre) & the plasma membrane remains (top right) of another bacterium burst by lysis, due to effects of antibiotics. Lysis occurs through the destruction of the outer plasma membrane (appears blue around complete bacterium), & the release of intracellular contents into the surrounding medium. S. aureus (a species of spherical, non-motile, Gram-positive bacteria) is responsible for pus containing infections such as boils and abscesses. S. aureus also secretes an exotoxin causing a type of acute gastro-enteritis. Magnification: X 17, 500 at 35mm size

© CNRI/SCIENCE PHOTO LIBRARY