Escharoides bidenkapi ( Kluge, 1946 )

Kuklinski, Piotr, Taylor, Paul D. & Denisenko, Nina, 2007, Arctic cheilostome bryozoan species of the genus Escharoides, Journal of Natural History 41 (1 - 4), pp. 219-228 : 221-223

Escharoides bidenkapi ( Kluge, 1946)

( Figure 2 )

Peristomella bidenkapi Kluge 1946, p 200 , Plate 2, Figure 6.

Escharoides bidenkapi: Kluge 1962, p 566 , Figure 400; Kluge 1975, p 690, Figure 400; Hayward and Ryland 1978, p 150, Figure 5A, B .

Escharoides jacksoni ( Waters, 1900) : Hayward and Ryland 1999, p 116, Figure 33.

Type material examined

Lectotype: ZI 30/2945, Kara Sea, ‘‘Sadko’’ Stn 58/98, 12 September 1935, det. Kluge from Gorbunov material, Kluge Collection. This specimen from the Kluge Collection is here chosen as the lectotype based on the match between the locality information and that given in the original description ( Kluge 1946).

Other material examined NHM 1911.10.1.1037, Greenland, 72 ° 109N, 20 ° 379E, depth 364–546 m, Norman

Collection ; NHM 1911.10.1.1045, Kvenanger Fjord, Finmark, Norway, April 1899, 100 m depth; NHM 1985.1.2.67, 51 ° 109N, 11 ° 479W, 1390–1582 m, 26 June 1960, Sarsia Stn 21/2; NHM 2006.07.31.1, Belgica Bank, East Greenland, ‘‘ Polarstern’ ’ Expedition, coll. Bader ; ZI 36/5223, Barents Sea , Kolski Bay, 13 August 1908, Trawl, det. Kluge, coll. Avrucev ; ZI 38/5468, Polar Basin , Stn 12, ‘‘ Litke’ ’, 14 September 1955, det. Gostilovskaya, coll. Koltun ; ZI 12, Shokalski Strait (located north of Wilkitzki Strait ), 77 ° 569N, 103 ° 339E, Stn 26, 6–7 September 1932, ‘‘ Rusanov’ ’, trawl, det. Kluge, coll. Vagin ; ZI 1, Kara Sea , Dickson Island–Cape Cheluskin , Stn 26, ‘‘ Sibiriakov’ ’, trawl, 28 August 1933, det. Kluge, coll. Gorbunov.

Description

Colony forming a thick unilaminar crust ( Figure 2A ). Ancestrula ( Figure 2D ) tatiform, oval, with narrow cryptocyst, broad proximal gymnocyst, and 14 spines.

Autozooids large, irregular in shape, separated by deep grooves, 0.61–1.03 mm long (mean 0.84 mm, n 520) by 0.50–0.76 mm wide (mean 0.62 mm, n 520). Frontal shield usually granular with polygonal surface patterning, bordered by a single or double row of round areolae. Orifice suborbicular; distal border with a broad, crenulated suboral shelf ( Figure 2C ); proximal edge developed as a thick, projecting peristome with usually three (one median and paired lateral) thickened denticles around proximal inner margin, and with a median notch on the rim. Denticles and notch sometimes missing. Denticles when present striated. Oral spines usually numbering four, short, thick, the outer two fused with the peristome. Ovicellate zooids have only two visible oral spines. Avicularia typically paired at distolateral corners of autozooids, sometimes single, very rarely lacking, large, 0.17–0.28 mm long (mean 0.23 mm, n 520) by 0.09–0.13 mm wide (mean 0.11 mm, n 520), directed distolaterally, rostrum narrowly triangular, hooked at tip, avicularian chamber often with pores at the base and rarely on the chamber itself; mandible elongatetriangular, crossbar calcified.

Ovicell ( Figure 2B ) hyperstomial, globular, finely granular, slightly longer than broad, large, 0.33–0.52 mm long (mean 0.42 mm, n 520) by 0.39–0.56 mm wide (mean 0.47 mm, n 520); pesudopores scattered over distal part, bordered by a series of round areolae.

Distribution

This Arctic and deep-water temperate species has been most frequently recorded from the Atlantic part of the Arctic. There are some records from the East Siberian Sea but none so far from the Canadian Arctic, which means that E. bidenkapi is probably not circumpolar in distribution. The species has been recorded as far south as the Bay of Biscay, at depths of 1390–1582 m in the temperate Atlantic ( Hayward and Ryland 1978).

Figures

Figure 2. Escharoides bidenkapi (Kluge, 1946), bleached. (A) Colony showing autozooids and ovicellate zooids (lectotype: ZI 30/2945); (B) ovicellate zooid with two lateral avicularia (ZI 36/5223); (C) orifice of autozooid with two lateral avicularia and characteristic suboral shelf with distal crenulation (ZI 38/5468); (D) ancestrula and surrounding zooids (ZI 38/5468). Scale bars: 100 mm (A, C); 200 mm (B, D).

Figure 5. Escharoides bidenkapi (Kluge, 1946) (black arrow) growing on a colony of Escharoides jacksoni (Waters, 1900) (white arrows) (ZI 1), bleached.