mesenterium
190
mesenterium (mesentery) (1) vertical partitions in coelenteron of Anthozoa; (2) in
vertebrates: double layer of peritoneum attaching stomach, intestines,
spleen etc. to dorsal wall of peritoneal cavity.
mesh size size of the openings in fishing nets or plankton gauze, measured
according to standard methods. The gauze of plankton nets consists of single
nylon fibers of a certain diameter, woven and melted together to form square
pores that are stable in form. Mesh size of different plankton nets is given in
Ilm length of the side of the square opening, irrespective of the diameter of
the surrounding fiber, and ranges from 20 to 2000 Ilm with SO, 100, 200, 300,
500 and 1000 f!ID being the sizes most frequently used in plankton research.
The nets used in fisheries are made of a great variety of natural and artificial
fibers, which can be woven or knotted in many different ways into the netting. Since the mesh openings are not stable in form, and the fibers are sometimes elastic, mesh sizes are measured in a way standardized by the ICES
(-jfishery science). A measuring device is brought diagonally into the mesh
opening and stretches it completely with a certain standard force, to measure
the "stretched mesh size", the measure used in the minimum mesh size regulations for fisheries for the protection of young fish.
mesocosms in- or outdoor established experimental ecosystems on a mesoscale, i.e., having a volume of between 1 and 10 4 m 3 in pelagic systems and a
surface area of> 1 m 2 in benthic systems. Microcosms or microecosystems refer
to smaller experimental systems. Mesocosms provide realistic facilities for
basic marine biological research, ecotoxicological testing, and aquaculture
experiments and bridge the gap between laboratory experiments and field
research.
mesoderm the middle tissue layer of an animal embryo, developing into tissues
between gut and ectoderm: muscles, blood vessels, connective tissue, etc.
mesogloea the jelly-like more or less structureless mass, filling the space
between the ectoderm and endoderm of the Cnidaria.
mesopelagic zone -jzonation.
mesophile a term referring to organisms living in the temperature range around
that of warm-blooded animals (-jhomeotherm).
mesoplankton planktonic organisms of intermediate body size between 0.2 and
2 mm, -jplankton.
mesosphere -jearth's internal structure.
190
mesenterium (mesentery) (1) vertical partitions in coelenteron of Anthozoa; (2) in
vertebrates: double layer of peritoneum attaching stomach, intestines,
spleen etc. to dorsal wall of peritoneal cavity.
mesh size size of the openings in fishing nets or plankton gauze, measured
according to standard methods. The gauze of plankton nets consists of single
nylon fibers of a certain diameter, woven and melted together to form square
pores that are stable in form. Mesh size of different plankton nets is given in
Ilm length of the side of the square opening, irrespective of the diameter of
the surrounding fiber, and ranges from 20 to 2000 Ilm with SO, 100, 200, 300,
500 and 1000 f!ID being the sizes most frequently used in plankton research.
The nets used in fisheries are made of a great variety of natural and artificial
fibers, which can be woven or knotted in many different ways into the netting. Since the mesh openings are not stable in form, and the fibers are sometimes elastic, mesh sizes are measured in a way standardized by the ICES
(-jfishery science). A measuring device is brought diagonally into the mesh
opening and stretches it completely with a certain standard force, to measure
the "stretched mesh size", the measure used in the minimum mesh size regulations for fisheries for the protection of young fish.
mesocosms in- or outdoor established experimental ecosystems on a mesoscale, i.e., having a volume of between 1 and 10 4 m 3 in pelagic systems and a
surface area of> 1 m 2 in benthic systems. Microcosms or microecosystems refer
to smaller experimental systems. Mesocosms provide realistic facilities for
basic marine biological research, ecotoxicological testing, and aquaculture
experiments and bridge the gap between laboratory experiments and field
research.
mesoderm the middle tissue layer of an animal embryo, developing into tissues
between gut and ectoderm: muscles, blood vessels, connective tissue, etc.
mesogloea the jelly-like more or less structureless mass, filling the space
between the ectoderm and endoderm of the Cnidaria.
mesopelagic zone -jzonation.
mesophile a term referring to organisms living in the temperature range around
that of warm-blooded animals (-jhomeotherm).
mesoplankton planktonic organisms of intermediate body size between 0.2 and
2 mm, -jplankton.
mesosphere -jearth's internal structure.