Stylissa carteri ( Dendy, 1889 )

George, Anita M., 2022, Tale of two species of Stylissa (Porifera: Demospongiae: Scopalinida) from the west and east coasts of India, Zootaxa 5178 (1), pp. 72-80 : 76-78

Stylissa carteri ( Dendy, 1889)

Fig. 3 A–F

Acanthella carteri Dendy, 1889: 93–94 , pl. 4, fig.6; 1905: 193, pl.8., fig.6.

Phakellia carteri ( Dendy, 1889) (genus transfer).

Axinella carteri ( Dendy, 1889) (genus transfer); Burton 1937: 35, pl. 6, fig.37; Thomas 1986: 290, pl. IV, fig 24.

Acanthella aurantiaca Keller, 1889: 396–397 , pls. XX – XXV.

Materials examined. ZMA. Por. 17154, Manauli Island, 9.02°N 79.13°E Gulf of Mannar, Tamil Nadu State, southeast India, 4 m, snorkelling, coll . AMG, 11 November 2000 . ZMA. Por. 17193, Melakkal, offshore Muttom, 8.12°N 77.31°E Tamil Nadu, southwest India , SCUBA 15m, coll. RD Sluka, 26 February 2002 . ZMA. Por. 19235 Vizhinjam Village, 8.37°N 76.98°E, Kerala State, 14 m; coll . AMG, 3 December 2003 . ZMA Por. 19207, Kadmat Island, 11.13°N 72.78°E, Lakshadweep Islands, 27 m, coll . AMG, 13 February 2005 . ZMA. Por. 19243, Minicoy Island, 8.52°N 55.11°E, Lakshadweep Islands, 35 m, coll . AMG, 12 December 2005 . NIOPor.3277. Lak 07, Kavaratti Island, 10.55°N 72.63°E, Lakshadweep, 14 m, coll . AMG. 21 October 2019 .

Type locality. South India and Sri Lanka ( Dendy 1889) .

External morphology. Specimens erect, fan-shaped, compressed and lobate with a broad base. Prolifically branched, thin lamellae with sinuous margins. Specimens 13–16 cm height and 5–10 cm width. Colour orangered and yellowish when fresh ( Fig. 3A ); pale yellow when dried and pale pink when in ethanol ( Fig. 3B ). Surface irregularly conulose and ridged. Smooth surface between blunt conules was found in the fresh specimen while the dried specimen was rough in texture. Oscules (2–3 mm) irregularly scattered.

Skeleton. Irregular network of stylote spicules. Spongin fibres are semitransparent (133–140 µm thickness and mesh size 20–30 µm) and spicules are plumosely arranged ( Fig. 3C ). Some areas of the network are opaque and some have vacant spaces. A small line of granules formed the external cortex.

Spicules. One type of style (both thin and thick), mostly stout rounded base and slightly curved and tapered and slightly curved tips. Thick styles (length 320.5– 410.17 –465.89 µm; width 9– 11 –15 µm) are more than the thin styles (length 293.5– 341.73 –398.58 µm; width 9.93– 13 –14.5 µm) ( Figs 3D–E ). Few oxeas were found ( Fig. 3F ).

Distribution and ecology. Common in the Indo-West Pacific, Eastern Indonesian reefs and Australia ( Hooper & Van Soest 2002).

Remarks. Stylissa carteri was the only record of Stylissa from the southwest Indian coast. It was originally described as Acanthella carteri ( Dendy, 1889) , recorded again by Dendy (1905) and Axinella carteri ( Burton 1937; Thomas 1986) from the Gulf of Mannar.

The new records of this species presented here from India, with erect, lamellate morphology, orange-red colour live condition, and irregularly arranged curved stylote spicules in a fibrous skeleton, match the type specimen of Acanthella carteri Dendy, 1889 and its junior synonym Acanthella aurantiaca Keller, 1889 . Also, the present specimens match the morphology of Axinella carteri (sensu Thomas, 1986) from the Gulf of Mannar, with its lamellate and grooved texture, the brick red colour and semitransparent spongin skeleton, Conversely, spicule measurements of the present specimens from South India differ from those recorded by Thomas (1986), which had stout styles (396–641 x 21–29 µm) and slender styles (901– 1470 x 7–15 µm), compared to styles of the current specimens which are less than 500 µm long and also the slightly curved points of styles were absent in Thomas’s (1986) specimens (which are probably an Axinella sp. )

A detailed comparison of S. carteri with other Stylissa species from the adjacent regions are presented in Table 1 .

Figures

FIGURE 3. Stylissa carteri (Dendy, 1889). A. Specimen NIO Por.3277.Lak07 showing planar, compressed, fanshaped form; scale bar = 5 cm. B. Specimen ZMA Por. 17154, showing the upright and compressed, lobate form, scale bar = 5 cm. C. Specimen NIO Por.3277.Lak07 section of showing the semi-transparent, ill-defined reticulation with styles; scale bar = 1 mm. Figs 3D–F. Spicules. D. Thick, rounded base and pointed tip, scale bar = 10 µm. E. Thin, smooth, gently curved styles, scale bar = 100 µm. F. Thin oxeas, scale bar = 100 µm.