No Toad in the hole!
Well, not a Toad in the hole, rather spawn in the pool courtesy of the local Frogs. The un-seasonal mild weather has tempted them to spawn in a quiet pool in the Wern Ddu woods near Caerphilly. Hopefully, the potential for hard frosts will stay away and they have a fighting chance to reach the tadpole stage
Frogs' embryos are surrounded by several layers of
gelatinous material giving them an almost 'jelly' like appearance. When several eggs are clumped together, they are
collectively known as frogspawn. The jelly provides support and protection
while allowing the passage of oxygen, carbon dioxide and ammonia. The spawn absorbs
moisture and swells on contact with water. After fertilisation, the innermost
portion liquefies which allows movement of the developing embryo. Most eggs are
black or dark brown and this has the advantage of absorbing warmth from the Sun
which the insulating capsule retains.
The larvae developing in the eggs can detect
vibrations caused by nearby predatory wasps or snakes, and will hatch early to
avoid being eaten. In general, the length of the egg stage depends on the
species and the environmental conditions. Aquatic eggs normally hatch within
one week when the capsule splits as a result of enzymes released by the
developing larvae. It is always a nice sight to see the spawn and is something I always look out for around this time of year - although this is the earliest I have seen some for a while. As I produced the spawn an adult Frog dived into the water and out of sight, leaving some tell-tale bubbles behind, but not not be seen again.
Those that make it to adulthood develop into what we generally see around our ponds, and the skin is smoother than that of the Toad which is darker and 'warty'.
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