Marine Invertebrate Safari

These photos are mostly from a recent family trip to the Georgia Aquarium. My mom took lots more photos of the whale sharks, skates and rays than of marine invertebrates, though, so a couple of pictures are from an earlier trip to the New York Aquarium.

My assignment was to do a photo safari of marine invertebrates, and identify their phylum and what features identify them as belonging to that phylum. I was supposed to identify them down to class or order if I could, and create a cladogram showing their evolutionary relationships.

In this first photo, we have two different creatures. First, there's a Sea Star, of the Phylum Echinodermata, Class Asteroidea. You can tell this by its pentaradial symmetry, its spiny skin, and by the thick attachments of its arms to the central disk. There is also an anemone in this photo, Phylum Cnidaria, Class Anthozoa. It has the radial symmetry and tentacles of a cnidarian, but it is sessile as an adult and has a polyp body form.

This second photo of anemones is of the bubbe tip anemone Entacmaea quadricolor of the phylum Cnidaria, Class Anthozoa.

This is some sort of clam, in the Phylum Mollusca, Class Bivalvia. It has two shells.

Here is a table coral. It is a Cnidarian (phylum), Anthozoan (Class), Sclereactinian (Order) coral. I know this since it is part of a larger reef structure, which are made by scleractinians.

This is a moon jelly, Aurelia aurita. Because it has radial symmetry, and tentacles with stinging cells, it must be a cnidarian. And due to its round bell with tentacles all along the rim, it has to be a member of class Scyphozoa, i.e., a true jellyfish.

Pictured here is a Japanese sea nettle, Chrysaora pacifica. It is also a Cnidarian, and a Scyphozoan, for the same reasons as above.

This is a Japanese Spider Crab, scientific name Macrocheira kaempferi, of the Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, and the Order Crustacea. I can tell that it is an arthropod based off its jointed legs, and that it is a decapod because it has ten legs.

This is a Nautiloid. It is from Phylum Mollusca, Class Cephalopoda. This is evident by its soft body with multiple tentacles, and its siphon for jet propulsion, as well as the fact that it has a shell.

This is a sea fan, a soft coral, from phylum Cnidaria, Class Anthozoa, Subclass Octocorallia.

It has a sessile polyp body form as an adult, lacks tentacles or an osculum, spongeocoel, or ostia, so it isn't an anemone or a poriferan, and must be a coral. It does not have a hard calcium carbonate skeleton, so it is a soft coral.

This is a sea urchin, of the Phylum Echinodermata and the Class Echinoidea. I can tell this because of the spiny skin, and the Aristotle's Lantern that is clearly visible.

This is a white striped cleaner shrimp, Lysmata ambonensis. Phylum Arthropoda, Subphylum Crustacea, Class Decapoda, which I know because of its ten, jointed limbs and hard carapace/exoskeleton.

>

This is a sea snail, of Phylum Mollusca, Class Gastropoda. it has a radula, a soft foot, and a helical shell with one opening.

The second part of my assignment was to create a cladogram showing the evolutionary relationships between the animals I chose.