Sporochnus bolleanus

Sporochnus bolleanus Montagne

Sporochnus bolleanus Montagne, 1856:393.

A subtidal collection from 23 m depth, off Roca Blanca, in Puerto Refugio, Isla Angel de la Guarda (lat. 29°33′04″, long. 113°33′51″) 21 Apr 1974, JN-5264a & b (US), (leg. JN), is the first record of the occurrence of this genus in the Gulf of California. Previously S. bolleanus has been known in the Pacific from the west coast of Baja California (Dawson, Neushul, and Wildman, 1960), the Galapagos Islands (Taylor, 1945), and in the Atlantic from the Gulf of Mexico (Earle, 1969), Bermuda, Puerto Rico, and Brazil (Taylor, 1960).

Sporochnus bolleanus is somewhat similar to S. pedunculatus but whereas the latter is delicate, slender, and smaller in size, S. bolleanus is a coarser plant, larger in dimensions throughout. Our specimens have intermediate vegetative measurements between S. bolleanus Montagne and S. pedunculatus (Hudson) C. Agardh (1820) as they were reported from the Gulf of Mexico (Taylor, 1960; Earle, 1969). Earle (1969) has noted difficulty in separating S. pedunculatus and S. bolleanus in some material from the northeastern Gulf of Mexico. There some plants may have young branches resembling S. pedunculatus and mature branches with the characteristics of S. bolleanus.

In specimens where the length of the determinate branchlets (pedicel, swollen fertile portion and tuft of hairs) are intermediate between these two species, the shape of the fertile part may be important in determining the species (Taylor, 1960). The fertile part of the Gulf of California material is cylindrical and elongate (Figure 4a,b), conforming to the description of S. bolleanus, while the fertile parts of S. pedunculatus are shorter and rounded, tending toward spindle-shape (Taylor, 1960:253, pl. 35: figs. 2–5; cf. Earle, 1969:190, figs. 89–92).

On the Pacific Coast of North America Sporochnus pedunculatus is recorded from Santa Catalina Island, off southern California, to Laguna Ojo

de Liebre (Scammon’s Lagoon), Baja California (Abbott and Hollenberg, in press).