Introduction

Figure A-1.

B. violaceus in relation to the rest of life. It is more closely related to us than many animals because it has a vertebrate-like notochord during its juvenile (tadpole) stage.

Figure A-2. B. violaceus colonies on boats and docks in Sausalito.

Figure A-3.

One B. violaceus colony up close (illuminated with red laser, field of view about 4 x 6 mm). The blue clumps on the surface of the colony are fecal pellets deposited by other animals.

Figure A-4.

Young B. violaceus colony growing on a microscope slide hung from dock for three months (illuminated from below by transmitted white light; field of view about 2 x 3 mm).

Figure A-5.

There are many species in the genus Botryllus, although only a few are common here. Colors range from white to yellow to orange to violet (violaceus means violet). Appearance also depends on the substrate the colony attaches to. In this picture we see at least 3 kinds of Botryllus, while the colony in the upper right might be a sponge. If you touch the intake vent and it immediately closes, it’s a tunicate; otherwise it’s a sponge!