What does a sea cockroach look like? The difference between sea cockroaches and cockroaches what are the characteristics of sea cockroaches

I believe that many people must also often see groups of martial arts masters climbing on the rocky reefs, artificial structures such as wave breakers, or the banks of fishing ports, crawling through the vertical walls of the turbulent waves at lightning speed, traversing all kinds of rugged terrain along the coast. They are commonly known as "sea cockroaches".

The word cockroach intuitively conjures up images of dirty gutters, dirty kitchens, and even cockroaches in the corner of toilets. This annoying title of public enemy number one makes most people shy away from sea cockroaches at the first smell of their name, thus losing the opportunity to know this magical creature.

This cockroach is not that cockroach.

This group of special forces living in the coastal rocks is not the same as kitchen cockroaches. Sea cockroaches are not insects. Although they are classified as Arthropods, sea cockroaches belong to the isopod order of the subclass Mollusca. Isopods are widely distributed, ranging from rodents under forest litter to sea cockroaches on the coast and water lice in the deep sea.

The Chinese official name of the most common sea cockroach on Taiwan's coast is "strange sea cockroach," scientific name Ligia exotica Roux, belonging to the family Ligiidae. The sea cockroach has seven pairs of appendages, which grow on the seven-segment chest, unlike the cockroach, which belongs to insects and has three pairs of legs. Careful observation shows that the structure of sea cockroach and cockroach is very different, and there is not much correlation in blood relationship. It is purely because of its appearance, movement mode and speed, so it is commonly known as sea cockroach.

Sea cockroaches climbing on gravel beaches can be seen to have seven pairs of ventral limbs.

It is widely distributed along the Pacific Ocean and Indian Ocean coasts and is the most common crustacean found along the coast of Taiwan. They are about 2 to 4 cm long, and their vertically flattened body reduces the resistance of waves.

These sea cockroaches like to inhabit the intertidal zone of the seashore, occasionally going up to the freshwater area near the estuary, often crawling in groups between the gravel or slope blocks, moving quickly, and can climb underwater to avoid enemies when encountering danger.

The most important recycler on the coast

Cockroach usually moves near the high tide line of the coast. Most of the time, it will not enter the water, but it will temporarily climb into the sea water when it is dangerous. Its flat body is conducive to its charge on the turbulent intertidal rocks, shuttle through the broken wave area and hide in the rock crevices. Like lightning troops, it comes and goes in waves, shuttles through gravel areas, reef areas, artificial facilities such as port docks, wooden piles and fishing boats, and even takes ships or driftwood as its home. These ninjas can be found in wetlands and fish ponds near coastal estuaries, and even in filter tanks and drains of aquariums in metropolitan areas.

Thus, the sea cockroach, equipped with the light-body technique of gliding over waves and climbing over rocks, can move freely in the treacherous surf zone. It can even climb to the cliffs of the coast and use its light-body technique to pick up all kinds of organic debris on the wave line of the intertidal zone, such as algae fragments, drifters and algae on rocks. In addition, small organisms, animal carcasses and bait abandoned by fishermen are all their feast. They do not waste any food at all. They can be called important resource recyclers on the beach.

According to the literature, sea cockroaches breed in spring, they are dioecious and oviparous organisms, so occasionally pairs of mature sea cockroaches are seen on intertidal rocks, with males clinging to females. Despite this, their movement speed is still very fast, without any hindrance, and their extreme movement and balance ability are amazing.

Diversified species distribution, showing the beauty of nature

In addition to living in the intertidal zone, a group of isopod species have also been found in deep-sea environments, and parasitic species have been found in both marine and freshwater. In marine museums and aquariums at home and abroad, species of large-scale dumplings such as Cirolanidae living in the deep sea have also been displayed. They have a pair of big eyes as deep as aliens in science fiction films. They are composed of about 4,000 small eyes combined into compound eyes. The color is pale purple, and there are two pairs of tentacles on the head, which is full of avant-garde feeling.

Among them, the largest is Bathynomus giganteus A. Milne-Edwards,1879), also known as giant deep-sea lice, giant isopods, giant isopods up to 45 cm, 1.5 kg, habitat in the Pacific Ocean, Indian Ocean and Atlantic waters deep sea sand bottom, huge size can be called the world's largest arthropod.

In addition, another deep-sea cockroach species, Bathynomus doederleinii Ortmann (1894), is often seen in bottom trawl catches off the coast of Taiwan. This species is distributed south of Honshu, Japan, and is also found in deep-sea waters off the coast of Taiwan in the temperate North Pacific Ocean. It inhabits depths of 150 to 600 meters and can reach 15 cm in length. It feeds on carrion in deep-sea environments. This group of floating water lice also has seven pairs of articulated limbs, and the first ventral limb is specialized into jaws, which can feed food into the mouth. This group of scavengers in the deep-sea benthic environment can quickly find dead marine organisms or injured individuals who have lost their ability to move. Therefore, they were previously captured in lamprey cages or crab cages in Donggang. Usually, when they encounter food, they will eat a lot. After a full meal, they can endure hunger for a long time.

There are many different habitats on Earth, and various species live in different ways in different environments. In the intertidal zone, where the temperature difference between day and night is high and the tide is low, the strange sea cockroach climbs the reef wall to survive in the waves and collects organic debris. In the extreme environment of deep sea and cold, the foot worm has tenacious vitality and special physiological functions. It is ready to eat at any time. After a big meal, it enters a hungry state and lurks for the next meal. The diverse habits of diverse species allow us to see more natural wonder and beauty.

Close-up of the head and eyes of the deep water louse, hyphophorus dowi.

The king has a worm.

Profile view of the deep water louse, daw's.

Abdominal view of the deep water louse, dau.

● This article is authorized to be reproduced from the April 2019 issue of Fishermen. Please do not reprint it directly.