Lab Activity 9.3
Biota 1: Seaweeds Found in Tidepools

  Directions

Study the instructional material below. Be sure to click on each of the photographs for an enlarged view in a separate window. The larger version is necessary to complete the assignment. It opens in a separate window which can be resized by grabbing the bottom right corner and dragging it. It can also be moved by grabbing the top heading bar and dragging it. Be sure to close the extra window by using the X in IBM, or the close box in MAC when you are finished using them.

  Introduction


In this lab activity you will study the seaweeds of tidepools.

Top  Instruction

Use the information below to fill out the checklist of the biota of tidepool microhabitats.

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.

 
Supporting Information
Refer to the Assigned Readings Below:
Marine Biology Textbook none
Marine Biology Coloring Book none
 

This picture gallery summarizes the seaweeds found in tidepools at Playa Estacion, Puerto Penasco, Sonora, Mexico.

It should be used to complete lab activity 9.3.

 

Sargassum sinicola

"Leafy grape weed"
Division  Phaeophyta
Class  Phaeophyceae
Order   Fucales
Family   Sargassaceae

Morphology Long, narrow, leaf-like blades with toothed edges. Smooth stem-like stipes and spherical, gas filled vesicles. Basal holdfast is short and branched. Brown color. To a foot or more in length.
Habitat On shallow subtidal and low intertidal rocks and in tidepools
Distribution Gulf of California
Other

 

Sargassum johnstoni

"Johnston's grape weed"
Division  Phaeophyta
Class  Phaeophyceae
Order   Fucales
Family   Sargassaceae
Morphology Densely crowded, short, narrow, leaf-like blades. Small, elliptical, gas filled vesicles. Basal holdfast is short. Brown color. To a foot or more in length.
Habitat On shallow subtidal and intertidal rocks and in tidepools
Distribution Gulf of California
Other

 

Padina mexicana
"Fan weed"
Division  Phaeophyta
Class  Phaeophyceae
Order   Dictyotales
Family   Dictyotaceae
Morphology Fan-shaped blades that are branched at their narrow bases forming clumps. The blades have annular stripesand a band-like outer edge. Two to eight inches tall.
Habitat On rocks in the low intertidal and in tidepools
Distribution Northern Gulf of California
Other

 

Dictyota divaricata
"Branched fan weed"
Division  Phaeophyta
Class  Phaeophyceae
Order   Dictyotales
Family   Dictyotaceae
Morphology Flat Y-shaped branching pattern. Paper thin blades are branched in a single plane forming a fan. Three to six inches tall.
Habitat On shallow subtidal rocks and in tidepools.
Distribution Throughout the tropics including the Gulf of California
Other

 

Laurencia johnstoni

"Red Laurencie's weed"
Division  Rhodophyta
Class  Florideophyceae
Order   Ceramiales
Family   Rhodomelaceae

Morphology Bushy, dark red, fleshy, branches covered with short branchlets. Radial branching pattern (Christmas-tree like). Several inches tall.
Habitat Abundant in tidal streams and tidepools
Distribution Gulf of California
Other

 

Amphiroa subcylindrica

"Jointed coralline algae"
Division  Rhodophyta
Class  Florideophyceae
Order   Cryptonemiales
Family   Corallinaceae
Morphology Pink tufts of upright, jointed branchs arising from an encrusting base. Dichotomous branching pattern. To about 3 inches tall.
Habitat On subtidal rocks and in tidepools
Distribution Gulf of California
Other