Segmented Bodies

Group 5: Arthropoda

Segmented Bodies

Group 5 - Arthropoda: Approximately 75-80% of all animals on earth are members of the phylum Arthropoda. While most arthropods are terrestrial insects and arachanids, about 85,000 species have adapted to ocean life.

Harlequin Shrimp (Hymenocera picta)

The Harlequin Shrimp (Hymenocera picta) is a captivating marine crustacean native to the Indo-Pacific region. Renowned for its vibrant coloration and intricate patterns, it stands out in coral reef habitats. These specialized predators feed primarily on starfish, using their powerful claws to capture and consume their prey. Despite their small size, they play a significant role in regulating starfish populations, contributing to coral reef health. Harlequin shrimp are often found in pairs, exhibiting complex mating behaviors and forming long-term bonds. While they are popular among marine enthusiasts, their populations face threats from habitat degradation and overharvesting.

Pronghorn Spiny Lobster (Palinulirus

The Pronghorn Spiny Lobster (Palinulirus penicillatus) is a prized crustacean species inhabiting the tropical waters of the Indo-Pacific region. Named for its distinctive horn-like protrusions on its carapace, it's a master of camouflage among rocky reefs and coral formations. As nocturnal predators, they prey on small fish, mollusks, and crustaceans, contributing to reef ecosystem balance. Pronghorn Spiny Lobsters are also crucial to local fisheries, supporting coastal communities through sustainable harvest. Despite their economic importance, they face threats from overfishing and habitat destruction. Conservation efforts aim to protect their habitats and promote responsible fishing practices for their long-term survival.

The Arrow Crab (Stenorhynchus debilis)

The Arrow Crab (Stenorhynchus debilis) is a striking marine crustacean found in tropical waters of the Western Atlantic Ocean and the Caribbean Sea. Known for its elongated body and long, spindly legs, it resembles an arrow poised for flight. These agile predators feed on a variety of small invertebrates and algae, contributing to reef ecosystem balance. With their sharp eyesight and swift movements, they are adept hunters and scavengers. Arrow Crabs often seek shelter in crevices or among coral formations during the day, emerging at night to forage. Their presence adds to the biodiversity and complexity of coral reef environments.

Choose an Invertebrate Category

1. Sponges (Porifera)

2. Marine Worms

3. Shells (Mollusca)

4. Spiny Skins (Echinodermata)

5. Segmented Bodies (Arthropoda)

7. Cnidaria. Phylum Cnidaria consists of over 11,000 individual species of aquatic animals, including jellyfish, anemones and corals.

6. Cnidaria

5 Fun Facts - Arthropoda

Fun Facts Marine Arthropoda

There are three major groups of marine arthropods: crustaceans, sea spiders and horseshoe crabs.

Horseshoe crabs: Have existed for over 450 million years and have changed very little over time. They are important to the biomedical industry due to a unique compound found in their blue blood, which coagulates around toxic bacteria. Scientists used horseshoe crab blood to develop a test used to check medical equipment and injectable medicines for contamination.

Reproduction: Most marine arthropods reproduce sexually, through external fertilization. The mating process of crustaceans can range from a few minutes to several days. Some crustaceans can reproduce asexually through parthenogenesis. Through this process, females produce viable eggs without the need for male fertilization.

Defense: The main form of defense is by their hard exoskeleton. The exoskeleton protects the animal from many predators and also helps it to retain water, preventing it from drying our quickly. Several crab species are known as decorator crabs. Hiding in plain sight, these animals will attach pieces of anemones, algae, seaweed, shells, gravel and other materials to their exoskeletons. They will then freeze in place when a predator is near, blending with their environment.

Roles: Marine arthropods are an important part of the food chain in many ways by filter feeding, nutrient recycling, eating algae and cleaning parasites, dead skin and mucus from other animals in a symbiotic cleaning process.

Cleaning stations: Help to maintain the balance of life on a reef. Fish, turtles, rays and more congregate at these locations to be thoroughly cleaned by shrimp, crabs and small fish.