Fredericella borealis, Wood, 2022

Wood, Timothy S., 2022, Phylactolaemate bryozoans at the Zoological Survey of India and a taxonomic key to Indian Phylactolaemata, Zootaxa 5200 (2), pp. 401-435 : 415-416

Fredericella borealis n. sp.

( Figs 1b, e ; 12a, b )

Fredericella indica: Wood & Backus, 1992, p. 191 , 192, fig. 6; Wood 1989, p. 21 –23, fig. 11; Wood 1991, p. 495; 2001, p. 519; 2010, p. 451; 2019, p. 524.

Fredericella sultana: Rogick 1935, p. 250 , 251; 1937, p. 101, 102, fig. 1B; Bushnell 1965, p. 241, 242; Økland & Økland, 2001, p. 107 –122, fig. 1C, D

Holotype. NHMUK 2015.3 .14.1, Fredericella borealis , collected 23 September 1994 from traveling screens, Springfield City Water, Light & Power drawing water from Springfield Lake , Springfield, Illinois, USA (in ethanol).

Diagnosis. Statoblasts heavily reticulated, including areas immediately on either side of the suture, interstices about 5–6 µm in diameter.

Etymology. The Latin borealis (northern) refers to the northern distribution of the species in North America and Europe, in contrast to F. indica , known so far only from the Indian subcontinent.

Description. Colony appearing as narrow tubules with zooids and branches widely spaced; an early series of zooids growing along the substratum, those upright zooids later producing new series of branching tubules that may be largely free of the substratum; tubules lightly frosted to nearly opaque, with diameter of 0.18 to 0.37 mm., those along the substratum conspicuously keeled; 18–22 lophophore tentacles roughly equal in length and arranged in a circle around the mouth; statoblasts, formed within both attached and free branches, consisting of a naked capsule with no enveloping periblast; entire statoblast surface bearing a fine reticulum that extends to the suture, the reticulum more prominent on the frontal valve than the basal valve, thin vestiges of a weak attachment ring sometimes occurring on the basal valve and merging with a locally sclerotized portion of the ectocyst.

Distribution. This is the dominant fredericellid in North America; it has also been reported from Germany ( Massard & Geimer 1996), Japan ( Hirose & Mawatari 2011a), and Norway, especially north of the Arctic Circle ( Økland & Økland 2001).

Remarks. Two other fredericellid species are known to have similar reticulation on the statoblast: (1) Fredericella crenulata DuBois-Reymond Marcus, 1946 , known only from the vicinity of Lake Titicaca, the statoblast serrated around the entire suture ( Fig. 13c ); (2) Fredericella indica Annandale, 1909 , known only from India and Sri Lanka, the statoblast reticulation weakening and disappearing towards either side of the suture ( Fig. 1a, c, d ).

Figures

FIGURE 1. Fredericella statoblast valves with pitted exterior. (a) Fredericella indica statoblast valve showing a smooth surface at the ends, from Annandale’s type specimen, ZSI 3479, valve has curled upon drying; (b) Fredericella borealis showing pitted surface at the ends, from Magerøya Island, Norway; (c) Fredericella indica, lateral view showing smooth region near the suture, from NHMUK 1914.10.2.1, Colombo, Sri Lanka; (d) Enlargement of previous photo; (e) Enlarged view of suture area of F. borealis from Illinois, USA, showing reticulation extending to the suture. Scale bars for a–c = 100 µm, scale bars for d–e = 20 µm.

FIGURE 12. Fredericella borealis n. sp. (a) A fragment of the holotype colony showing free branches and several statoblasts, scale bar = 3 mm; (b) A pair of separated valves showing reticulation extending to the suture, scale bar = 100 µm.

FIGURE 13. Fredericella carinata n. sp. (a) Pair of statoblast valves, scale bar = 100 µm; (b) Closer view with SEM showing a portion of the carina, scale bar = 30 µm; (c) Similar feature in Fredericella crenulata, scale bar = 15 µm.