Copidozoum magnum, López-Fé, 2006

López-Fé, C. M., 2006, Some bathyal cheilostome Bryozoa (Bryozoa, Cheilostomata) from the Canary Islands (Spain, Eastern Atlantic), with descriptions of three new species, a new genus, and a new family, Journal of Natural History 40 (29 - 31), pp. 1801-1812 : 1805-1806

Genus Copidozoum Harmer, 1926

Copidozoum magnum sp. nov.

( Figures 4–7 ; Table II)

Material

Many colonies on different pieces of Madrepora oculata .

Holotype: a complete colony with ovicells ( MNCN 25.03 /3723) . Paratype: young colony with ancestrula ( MNCN 25.03 /3723) .

Other material. Numerous colonies on ‘‘ Madrepora 1’’ (MNCN 25.03/3729) and ‘‘ Madrepora 2’’ (MNCN 25.03/3735).

Description

Colony encrusting and unilaminar. Autozooids oval, with a narrow gymnocyst and very narrow cryptocyst. A large opesia occupies most of the frontal surface. Each autozooid bears a pair of caduceous oral spines, but there are no marginal spines except in the ancestrula and first zooids. Ovicell hemispherical, with semicircular orifice, fully calcified, with a narrow rim and two lateral ridges around the aperture. The ovicell is situated on a kenozooid, which may be seen at the colony margins, and in broken areas, as a small space below the ovicell, separated by pore chambers from both the maternal and the succeeding zooid. Intrazooidal budding by uniporous chambers. Avicularia interzooidal, triangular, with a hooked rostrum. Ancestrula tatiform, similar to autozooids in shape, but with 11 spines. The first postancestrular zooid has six spines in its distal half, and some of the subsequent zooids may have four.

Etymology

Magnum (5large) refers to the large size of the autozooids, compared with other species of the genus.

Discussion

The new species may be distinguished by its large zooids, thinly calcified and devoid of marginal spines, and by its ovicell lying on a kenozooid ( Figure 6 ). In this species, the ovicell is of the type C of Bishop and Househam (1987), in which the supporting kenozooid is very reduced to an underlying space beneath the ovicell, without any trace of frontal wall, but with its own communication organs. The autozooids and avicularia are similar in shape to those of Copidozoum exiguum ( Barroso 1920) , but this species has small zooids with 8–10 marginal spines ( Barroso 1920; Zabala and Maluquer 1988; Zabala et al. 1993; Hayward and Ryland 1998).

Two more species of Copidozoum exist in the Atlanto-Mediterranean region (sensu Ekman 1953): C. planum (Hincks) and C. tenuirostre (Hincks) . Both have few or no spines, but they have avicularia with narrow rostrum and the ovicells are not supported by a kenozooid ( Zabala and Maluquer 1988; Hayward and Ryland 1998). Only C. exiguum is found in deep waters, with a maximum known depth of 1097 m in the Bay of Biscay ( Hayward and Ryland 1978). Copidozoum planum and C. tenuirostre are always found in shallower depths than 200 m. Further, only C. tenuirostre is present on the Atlantic coast of Africa ( Cook 1968a, 1968b, 1985; Arístegui and Cruz 1986) while C. planum and C. exiguum are only known from the Mediterranean or Atlantic European coasts.

Figures

Figures 4–7. Copidozoum magnum sp. n.: (4–6) holotype (MNCN 25.03/3723); (7) paratype (MNCN 25.03/ 3723). (4) Autozooids, ovicells, and avicularia. (5) Avicularium. (6) Broken ovicell, with the basal kenozooid below. (7) Ancestrula (a) and first zooids, the small ancestrula at right (C.a.) belongs to Distansescharella alcicornis.