Intertidal Bryozoa (Cheilostomata) of Ketchikan, Alaska

Abstract

Assemblages of intertidal bryozoans are proving to be more species-rich than generally previously appreciated. This study found 31 species of cheilostome bryozoans at three rocky-intertidal sites at Ketchikan, Alaska, USA. Species richness varied considerably among the three collecting sites: 28 at East Tongass Narrows, 18 at Higgins Point, 10 at Settlers Cove. Each site had species not occurring at the other sites (12, two, and one species, respectively). The number of species per site was within the range of values previously observed in a more extensive study at Kodiak, Alaska, suggesting both similar intertidal species richness at the two localities, and that sampling of other intertidal sites at Ketchikan would detect additional species. Descriptions and scanning electron microscopy (SEM) illustrations are provided for the species found at Ketchikan, and SEM illustrations are included for

The Internal-Brooding Apparatus in the Bryozoan Genus Cauloramphus (Cheilostomata: Calloporidae) and Its Inferred Homology to Ovicells

“…Although in the course of this study we directly observed embryos in only two of the species examined (C. spinifer and C. cryptoarmatus), internally brooded embryos have been reported for all the species examined (Dick and Ross, 1988;Dick et al, 2005;Grischenko et al, 2007). These data coupled with our observation of ooecia in the eight species studied strongly suggest that a reduced, maternally produced kenozooidal ooecium and internal brood sac are characters common to all species of Cauloramphus and should thus be appended as diagnostic characters for this genus.…”

“…Hincks (1882, p. 250) indicated uncertainty in his original description of C. echinus by noting, "Ooecia (?)". Some species have been reported as having an inconspicuous, cap-like ovicell (e.g., Kluge, 1975;Mawatari and Mawatari, 1981;Dick and Ross, 1988). Despite previous reports of brood chambers in C. spinifer, Gostilovskaya (1978) noted for the White Sea population of this species that brood chambers were unknown.…”

“…Cauloramphus spinifer (Johnston, 1832); Cauloramphus magnus Dick and Ross, 1988; Cauloramphus cryptoarmatus Grischenko, Dick, and Mawatari, 2007; Cauloramphus niger Grischenko, Dick, and Mawatari, 2007; Cauloramphus multispinosus Grischenko, Dick, and Mawatari, 2007. Narrow Strait, Kodiak, Alaska, USA, September-December 1982:…”

“…disjunctus Canu and Bassler, 1929;and C. californiensis Soule, Soule, and Chaney, 1995. We suspect that failure to report brooding structures in Cauloramphus is due both to the difficulty of seeing the external parts of these structures without scanning electron microscopy (SEM) and to authors simply failing to understand the condition of the ooecium, which is reduced. For example, Dick and Ross (1988) reported ovicells as "not observed" or "lacking" in three of the five Cauloramphus species they reported from Alaska; in C. magnus, they noted a vague connection between the internal brooding of embryos by zooids and a raised, crescentic lip distal to the orifice. As another example, Seo (2001, p. 225) noted in her original description of C. korensis, "Ovicells not seen," yet she inadvertently described the ooecium with "Distal to the orifice, transverse crescentic cap much raised above the level of mural rims," and her illustrations of this species (Seo, 2001, Fig.…”

“…1B, C, 2005 clearly show a fairly substantial ooecium. Dick et al (2005) and Grischenko et al (2007) reported, but did not describe in detail, both ooecia and internal brooding in all seven species of Cauloramphus they treated between them, including five new species. This result suggests that an ooecium, reduced to a variable extent, and internal brooding are features common to all species of Cauloramphus.…”