Be sure to write about what you are learning in the lab section of your notebook. You will be expected to answer questions about the lab activity during the lab self test and lab quiz. It helps to have your text and coloring books open beside you for support.

This picture gallery summarizes the biota found in beachrock crevices at Playa Estacion, Puerto Penasco, Sonora, Mexico.

It should be used to complete lab activity 9.2.

Eriphia squamata
	"Lumpy-clawed Crab" Phylum  Arthropoda Class  Crustacea Order   Decapoda Family   Xanthidae
Morphology Its body (carapace) is usually 1-2 inches wide. It is mottled gray to green and its legs are banded with black. Feeding Feeds at night. Forages for worms, algae and smaller crabs. Defense Large claws that can pinch. Will defend its territory savagely. Hides during the day in holes or crevices. Reproduction Males pass spermatophores to females during copulation. Females carry fertilized eggs under abdomenal flap. Hatchlings are zoea larvae that develop in the plankton. Habitat Occurs in great numbers in the lower midintertidal zone of rocky shores. Distribution Ranges from upper Gulf to Ecquador and Galapagos Islands. Other One of the most common crabs - very territorial.

Modiolus capax
	"Horse Mussel" Phylum Mollusca Class Pelecypoda  Order  Mytiloidea Family  Mytilidae
Morphology A swollen orange-brown shell covered with a "beard" of serrated brown hairs distinguishes this mussel from any other. The shell lacks any strong sculpture. Feeding Filter feeders. Defense The serrated hairs provide camoflouge for the mussel as well as a place for other animals to grow. Can close its shell to conseve moisture - may also tightly close shell if disturbed. Reproduction Separate sexes and spawning. Habitat Intertidally on rocky substrate. Distribution Northern California to Peru and throughout the Gulf of California. Other

Echinometra vanbrunti
	"Purple sea urchin" Phylum  Echinodermata Class  Echinoidea Order   Camarodonta Family   Echinometridae
Morphology A dark purple urchin with long (one inch) slender spines. Feeding Graze on algae Defense The brittle spines may break off and cause puncture wounds that are very painful. Reproduction Separate sexes and synchronous spawning Habitat Intertidally on rocky substrate.Particularly in crevices and cavities in rocks and reefs, where it can avoid the full impact of the surf. Distribution Northern Gulf of California to Peru and Galapagos Islands. Other

Eucidaris thouarsii
	"Slate pencil urchin" Phylum  Ecinodermata Class  Echinoidea Order   Cidaroidea Family   Cidaridae
Morphology A brownish purple urchin with a test diameter of up to 3 inches and ten vertical rows of five to eight thick spines which taper to a blunt tip. Spines often encrusted with bryozoans and sponges. Feeding Grazing on algae and encrusting invertebrates Defense Can wedge itself into crevices using its spines Reproduction Separate sexes and synchronous spawning Habitat Crevices and cavities in rocks on reefs in the lower intertidal and subtidal Distribution Gulf of California south to Ecuador Other