Cyamon neon De Laubenfels, 1930

Soest, Rob van, Carballo, Jose Luis & Hooper, John, 2012, Polyaxone monaxonids: revision of raspailiid sponges with polyactine megascleres (Cyamon and Trikentrion), ZooKeys 239, pp. 1-70 : 23

Cyamon neon De Laubenfels, 1930 Figs 11 A–H

Cyamon neon De Laubenfels 1930: 28 (California); 1932: 109, fig. 65; Sim and Bakus 1986: 17 (California, with erroneous size data of the polyactines); Luke 1998: 10 (La Jolla, S California); Lee et al. 2007: 211.

Material examined.

Holotype USNM 21412, preserved in alcohol, California, between Point Dunes and Newport, near San Pedro.

Paratype: BMNH 1929.9.30.5, two slides, Santa Catalina Island, California, 33.5°N.

Description.

Shape massively encrusting (Fig. 11A) with irregular conulose-villose surface. Size of specimen 4 × 3 cm in lateral expansion, 2 cm in thickness. Color (alcohol) red brown.

Skeleton: columnar, with thick short styles at the center of a mass of polyactines, with long thin styles protruding from this skeleton surrounded by shorter centrotylote styles.

Spicules: long thin styles, short thin centrotylote styles, short thick styles, polyactines.

Long thin styles (Figs 11B, B1), relative straight and robust, frequently with subterminal tyle 860 –1041– 1290 × 6 –7.8– 10 µm (De Laubenfels gives: up to 1560 × 12 µm).

Short thin styles (Figs 11C, C1), curved, centrotylote, often with mucronate slightly rugose pointed end, 191 –242.8– 306 × 1.5 –2.4– 3 µm.

Short thick styles (Fig. 11D), smooth, curved evenly, occasionally oxeote, 270 –408.2– 468 × 14 –16.8– 24 µm.

Polyactines (Figs 11E, 11E1, 11F) robust, largely smooth with cladi spined only at the apices (Fig. 11E1), or all cladi smooth. The three- or four claded forms vary widely in size and are sometimes reminiscent of Trikentrion spicules. Three-claded forms tend to have longer and thicker lateral cladi than the rare four-claded forms. Basal cladi in three-claded spicules are 33 –48.8– 63 × 8 –11.7– 14 µm, lateral cladi 72 –95.7– 132 × 7-12 µm, while four-claded forms have basal cladi 40 –55.0– 69 × 6 –7.7– 9 µm and lateral cladi 30 –45.1– 57 × 5 –6.3– 7 µm. There are very common diactinal polyactines (Fig. 11F), mimicking oxeas, but recognizable as reduced polyactines by centrotylote swellings and finely spined apices, size 123 –158.3– 202 × 7 –10.2– 14 µm.

Distribution.

Southern Californian Bight (San Pedro, Santa Catalina island, La Jolla).

Ecology.

On hard substrate, at depths 0-36 m.

Discussion.

Cyamon neon is unusual among Cyamon species by it possession of polyactines with smooth or barely spined cladi, the shape of many of the polyactines mimicking those of Trikentrion , and the occurrence of diactinal polyactines. The latter spicules are shared with Cyamon argon , which in most respects is similar to Cyamon neon . For a comparison between the two species see below in the remarks to Cyamon argon . The only other Cyamon species in the area is Cyamon koltuni , which differs substantially in the bulbous endings of the cladi of the polyactines and absence of the short thin styles.