Spiny lobsters are capable of communicating and sounding warning calls by means of stridulation - the rubbing together of two body parts to make a rasping noise. Unlike crickets that stridulate by rubbing their wings together, these sea bugs (as crustaceans are sometimes called) produce sounds by moving their antennae. This results in a soft tissue called the plectrum to stick, then glide, stick, then glide - cello players know what I mean - over a file near the eyes, creating a sound something like running your finger down a comb. An advantage of this is that they can make these noises even when they are in the vulnerable time after moulting.
Spiny lobsters are capable of communicating and sounding warning calls by means of stridulation - the rubbing together of two body parts to make a rasping noise. Unlike crickets that stridulate by rubbing their wings together, these sea bugs (as crustaceans are sometimes called) produce sounds by moving their antennae. This results in a soft tissue called the plectrum to stick, then glide, stick, then glide - cello players know what I mean - over a file near the eyes, creating a sound something like running your finger down a comb. An advantage of this is that they can make these noises even when they are in the vulnerable time after moulting.
Once threatened from overharvesting, pressure on ula poni was relaxed a bit in 2000 when a commercial lobster fishery in the NWHI was closed, and the area was designated a protected marine sanctuary under the Hawaiian Islands Coral Reef Ecosystem Reserve. Here in the MHI, ula cannot be taken May through August, females are off limits year round, and males must have a carapace length of three and one quarter inches. Spearing is prohibited. Check http://dlnr.hawaii.gov/dar/fishing/fishing-regulations/marine-invertebrates/ for updates. Consider that it takes a good eight years for the lobsters to reach maturity. And further consider that overharvesting by humans means less for young monk seals.
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Every dog has its day, and it's today that the dogbane family gets a front and center post. It all started when I went out in my backyard this morning, marveling at the beautiful, vining Stephanotis in bloom. At the same time, the large seed pods of this plant have ripened, going from a smooth green pod, to a yellower, wrinklier version, and some have split open. Inside are lots and lots of tightly packed seeds, each with a silky sail. The seeds and pods so reminded me of milkweed, I had to get online to see if they were in the same family. And indeed, they are. Milkweed used to belong to its own family, but has recently been reclassified in a subfamily of the family Apocynaceae, (pronounced a-pos-ih-NAY-see-ee, or a-pos-ih-NAY-see-eye) the dogbane family. Dogbane members often (but not always) have a milky sap, which can be poisonous. Their leaves are simple (meaning the blade is whole - not divided into leaflets), and often opposite to each other (two leaves arise on opposite sides of the stem from the same node) or whorled (several leaves arise from the same level on the stem and encircle it). The petals may be fused or partially fused, and are usually five-lobed. With this general information, I began to look around my yard, and the plants in the neighborhood, thinking about which might be related. And, wow, it turns out many of our tropical ornamentals are in the dogbane family. I immediately thought of the crown flower, the plumeria and the yellow allamanda, a vining plant with yellow trumpet-like flowers, and yup - they're all in the family. Add to that list the natal plum, the Madagascar periwinkle, vinca, the be-still tree, maile, oleander, and mandevilla - and there's plenty more. Seems the neighborhood has gone to the dogs.
For three nights in a row, I have found one of these cone-headed katydids on the lanai, so I figured it was time to write a post on them. It is possibly Euconocephalus nasutus, an omnivorous and non-native conehead, though there are a number of endemic coneheads in the genus Banza. The brilliant green is part of their cryptic coloration, often resembling leaves, right down to the venation. They eat the leaves they blend in with, as well as other plant parts, and can do some damage - Elimaea punctifera is another non-native that can wreak havoc on hibiscus blossoms. Many katydids will dine on insects as well, such as aphids. In turn, they are a favorite meal of Jackson's chameleon, as well as bats, birds, spiders, and more. They are masters of stridulation, filling our warm nights with their vocalization, "katy did, katy didnʻt," though some sound more like buzzing or rasping bursts. Species vocalizations may be distinct and can be used to identify the musician. Grasshopper or Katydid?
Katydids, grasshoppers, and crickets are all in the same order, called Orthoptera, meaning straight-winged, and they share many characteristics: chewing mouthparts, strong hind legs for jumping, and a life cycle of incomplete metamorphosis: from egg, to nymph (which looks like a smaller and wingless version of the adult), and after several molts, an adult. There are some key differences, however (though there are always exceptions). Katydids have long, wispy antennae that are at least as long as their bodies, whereas grasshoppers' are shorter and stubbier. Both crickets and katydids produce their sounds by rubbing their wings; grasshoppers rub pegs on their legs to stridulate. Grasshoppers also tend to be diurnal, whereas katydids and crickets work the nightshift. |
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