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 under beachrock slabs at Playa Estacion, Puerto Penasco, Sonora, Mexico.

It should be used to complete lab activity 9.2.

Tethya aurantia
	"Golf ball sponge" Phylum  Porifera Class  Demospongiae Order   Hadromerida Family   Tethyidae
Morphology Golf-ball shaped, yellow-orange, warty sponge. It has root-like processes at its base that attach it to rock surfaces. Inside it has tough fibers that radiate out from the center. One to three inches in diameter. Feeding Filter feeding Defense Unpalatable Reproduction Asexual budding and sexual larval production Habitat On the undersides of rocks, rocky overhangs, caves and crevices in the lower intertidal and shallow subtidal Distribution Throughout the world's oceans including the Gulf of California Other Contain a layer of symbiotic algae just below their surface

Geodia mesotriaena
	"Fuzzy gray sponge" Phylum  Porifera Class  Demospongiae Order   Choristida Family   Geodiidae
Morphology Its color varies from white, gray, brown to purple on the outside and white or pale cream inside. The sponge spreads laterally into a massive cake, often forming very large colonies. Topped by leathery with many excurrent openings (oscula). A distinctive feature of this sponge is that the large pores(oscula) are restricted to sieve plates, which are leathery discs about 2-3 sm in diameter, with many openings. Its internal chambers shelter many other creatures including small porcelain crabs, brittle stars, and segmented worms. Feeding Filter feeding Defense Unpalatable Reproduction Asexual budding and sexual spawning Habitat Lives in the lowest tidal area under boulders. Distribution From southern Alaska to the Gulf of California. Other Predators are few including some nudibranchs and brittle stars. Its internal chambers shelter many other creatures including small porcelain crabs, brittle stars, and segmented worms.

Petrolisthes gracilis
	"Slender rock slider" Phylum  Arthropoda Class  Crustacea Order   Decapoda Family   Porcellanidae
Morphology Small, very flat, bluish-green crab with white spots. Small, fifth pair of legs folded over the back edge of the body. The legs and body are relatively hairless. Feeding Filter particles from water using the hair on their mouth parts Defense Hard exoskeleton and ability to cling to the undersides of stones in very cramped quarters Reproduction Separate sexes. Females brood eggs under their abdominal flaps until they hatch. Habitat Found under stones. Distribution From the upper Gulf of California and Bahia Magdalena to as far south as Bahia Tongola-Tangola, Mexico. Other

Petrolitshes hirtipes
	"Fringed rock slider" Phylum  Arthropoda Class  Crustacea Order   Decapoda Family   Porcellanidae
Morphology Small, very flat, brown crab with small, fifth pair of legs folded over the back edge of the body. The legs all bear a long fringe of hair. Feeding Filter particles from water using the hair on their legs and mouth parts Defense Hard exoskeleton and ability to cling to the undersides of stones in very cramped quarters Reproduction Separate sexes. Females brood eggs under their abdominal flaps until they hatch. Habitat Common under stones and in crevices of reefs, coral and sponges in the lower intertidal. Distribution Lower Pacific Baja and throughout the Gulf of California. Other

Pilumnus townsendi
	"Townsend's hairy crab" Phylum  Arthropoda Class  Crustacea Order   Decapoda Family   Xanthidae
Morphology Identified by four spines on the front outside edges of the body and spiny, hairy claws. Two different types of hairs on the purple body: one is long and stiff and the other is short and soft. Feeding Scavengers who feed on floating food particles. Defense Claws and hard exoskeleton and able to hide in small cavities Reproduction Separate sexes. Females brood eggs on pleopods until they hatch. Habitat Live under rocks and boulders; some prefer drainage channels in rocky areas where they have access to constant water. Distribution Upper gulf to Bahia Manzanillo. Other One of many hairy crabs living in the Gulf of California intertidal. Docile to handle, rarely large enough to pinch.

Alpheus californiensis
	"Snapping shrimp" Phylum  Arthropoda Class  Crustacea Order   Decapoda Family   Alpheidae
Morphology Colorful, fast, backwards swimming shrimp that are easily identified by their one large claw that is modified for making loud clicking or popping noises. Feeding Snap large claw to stun prey. Use claw to grab small animals or morsels of food floating by. Defense Hard shell on body (after molting, the body is soft. The shell hardens after a few hours, however, during that time they are vulnerable). Reproduction Separate sexes. Females brood eggs on pleopods until they hatch. Habitat Lives in tunnels under rocks in a sandy substrate. Distribution Southern California to the Gulf of California, common at Puerto Penasco Other If large claw is pulled off the other hand will develop a large claw.

Barbatia reeveana
	"Reeve's ark shell" Phylum  Mollusca Class  Pelecypoda Order   Arcoida Family   Arcidae
Morphology Large, white, ribbed shell with dark brown, fuzzy periostracum. Shape often distorted from growing between rocks. Feeding Filter feeder Defense Shell and ability to live in tight spaces Reproduction Separate sexes and spawning Habitat Under rocks in sandy or muddy areas of tidal flats and subtidally in lagoons Distribution Lower Pacific Baja, throughout the Gulf of California, south to Peru Other

Nerita funiculata
	"Small nerite" Phylum  Mollusca Class  Gastropoda Order   Archeogastropoda Family   Neritidae
Morphology Globular shell, black to gray, with spiral ribs. Inner lip of aperture with small nodules. Tight fitting operculum forms water tight seal. Commonly 0.75 inches in diameter. Feeding Scrapes algae from rocks. Defense Active on tops of rocks at low tide Reproduction   Habitat On rocks at high tide levels. Distribution Outer coast of Baja California, through the Gulf to Peru. Other Gregarious found in clumps of up to several hundred individuals.

Nerita scabricosta
	"Rough-ribbed nerite" Phylum  Mollusca Class  Gastropoda Order   Archaeogastropoda Family   Neritidae
Morphology Globular shell, black to gray, with spiral ribs. Inner lip of aperture with 4 large teeth. Tight fitting operculum forms water tight seal. Commonly 1.5 inches in diameter Feeding Scrapes algae from rocks. Defense Live high in the intertidal Reproduction   Habitat On rocks at high tide levels. Distribution Outer coast of Baja California, through the Gulf to Equador. Other Snail increases in size as one moves south in the Gulf.

Turbo fluctuosus
	"Turban shell" Phylum  Mollusca Class  Gastropoda Order   Archeogastropoda Family   Turbinidae
Morphology Top-shaped shell with a heavy calcarous operculum. Color is variable, from bright orange to dark green. Commonly 2.5 inches. Feeding Grazes on algae. Defense Closes its shell aperature with a hard, calcareous operculum Reproduction   Habitat Abundant on rocky shores. Distribution Throughout the Gulf of California and south to Peru and Ecuador Other Operculum is collected for jewelry. Best observed at night.

Diadora inaequalis
	"Orange keyhole limpet" Phylum  Mollusca Class  Gastropoda Order   Archaeogastropoda Family   Fissurellidae
Morphology Opening at top of cap-shaped shell; fleshy orange mantle; broad in middle and constricted at both ends. Feeding Graze on microscopic algae on rocks. Defense Clamp tightly to rocks and are protected by shell Reproduction Habitat Found on the underside of rocks in the intertidal. Distribution Throughout the Gulf of California, south to Galapagos Islands. Other

Selenkothuria lubrica
	"Sulfur cucumber" Phylum  Echinodermata Class  Holothuroidea Order   Aspidochirota Family   Holothruiidae
Morphology Maximum length of 15 cm, usually a sulfur-yellow color (tips of their feet), the base color ranges from gray-brown to purplish-black. Feeding Plankton eaters. Defense Will eject part of its stomach lining as a decoy when disturbed. Reproduction Separate sexes and spawning Habitat Under rocks in the lower mid intertidal zone in a cluster. Distribution Ranges from upper Gulf of California to Ecuador and the Galapagos Islands. 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

Aplidium sp.
	"Sea pork" Phylum  Chordata Class  Ascidiacea Order   Enterogona Family   Polyclinidae
Morphology Large, fleshy colonies made up of subunits. Each subunit contains many individuals arranged radially around an excurrent pore and covered by a gelatinous tunic. The colony is smooth and firm to the touch and from pale to vivid orange in color. Feeding Filter feeder. Each individual produces a ventilating current using a ciliated, sticky basket-like paharynx to strain particles from the water. Defense Produces distasteful, poisonous chemicals Reproduction Sexually produced tadpole larvae have all the characteristics of chordates and are somewhat fish-like. These settle and transform into sessile adults which bud to produce a colony. Habitat Under rocks in the intertidal and on rock surfaces in the subtidal. Distribution   Other