Latrunculia (Latrunculia) brevis Ridley and Dendy, 1886

Samaai, Toufiek, Gibbons, Mark J. & Kelly, Michelle, 2006, Revision of the genus Latrunculia du Bocage, 1869 Porifera: Demospongiae: Latrunculiidae) with descriptions of new species from New Caledonia and the Northeastern Pacific (, Zootaxa 1127 (1), pp. 1-71 : 33-35

Latrunculia (Latrunculia) brevis Ridley and Dendy, 1886

( Figs 1F, 2 , 3C, 4E ; Tables 2 & 3)

L. brevis Ridley and Dendy 1886, p. 492 ; 1887, p., 236, PL XLIV, FIG 5 , PL. XLV, FIG 8, 8A. L . brevis; Boury­Esnault and van Beveren, 1984: 45; L. lendenfeldi ; Burton, 1932: 340. L. lendenfeldi ; Burton, 1940: 118, PL. 6, FIG. 4 .

Holotype material. BMNH 1887.5 .2.269, ethanol preserved sample (light brown­beige subsample of specimen, 0.5 x 0.1 x 0.1 mm) and microscope­slides, off the mouth of Rio de la Plata, Argentina, stn 320, 37 17' S., 53 52' W; February 14, 1876; depth 1080 m, Challenger Expedition.

Other material examined. BMNH 1887.5 .2.270 (Type of var.) labeled Latrunculia brevis identified by Ridley and Dendy, 1887, off the mouth of Rio de la Plata, Argentina, stn 320, 37 17' S., 53 52' W; February 14, 1876, depth 1080 m, Challenger expedition . BMNH 1928.2.15.823a, labeled Latrunculia lendenfeldi identified by Burton, HMS Discovery investigation, Stn. WS 248, microscope­slide, depth 210–242 . BMNH 1933.6.10.28a, labeled Latrunculia lendenfeldi off SE coast of South America , Buenos Aires, Museum Exc. Coll. No. 1660, microscope­slide . BMNH 1933.6.10.29a, Labeled Latrunculia lendenfeldi off SE coast of South America , Buenos Aires, Museum Exc. Coll. No. 1660, microscope­slide . BMNH 1935.10.26.140a labeled Latrunculia lendenfeldi identified by Mawson , Mawson Antarctic Expedition coll. No. 2137, Antarctica, microscope­slide . BMNH 1935.10.26.142a labeled Latrunculia lendenfeldi identified by Mawson , Mawson Antarctic Expedition coll. No. 2139, Antarctica, microscope­slide . BMNH 1935.10.26.143a labeled Latrunculia lendenfeldi identified by Mawson , Mawson Antarctic Expedition coll. No. 2140, Antarctica, microscope­slide .

Description. Thickly encrusting to massive, semispherical sponge 6 x 4.5 x 5 cm diameter Fig 3C). Surface smooth, with volcano­shaped or conical oscules, 6 mm high and with mammiform areolate porefields, 0.5 x 0.5 mm in diameter. Ectosome thin and transparent, easily separable from underlying choanosome. Colour in life unknown; in preservative light brown­beige.

Skeleton. The choanosomal skeleton is a very loose irregular polygonal­meshed reticulation formed by wispy tracts of smooth styles ( Fig. 4E ). These tracts range in width from 45–91 µm in thickness but may form meshes that are 200 µm wide. There is no distinction between the primary and secondary fibres. Towards the surface of the sponge these spicules tend to be vertically arranged. The surface of the ectosome is lined with a layer of erect anisodiscorhabds.

Spicules. Megascleres: styles are smooth, centrally thickened, fusiform and slightly sinuous, 463 (455–482) x 14 (14) m, n=20. Microscleres ( Fig. 1F) anisodiscorhabds with a small manubrium, above which is a basal whorl. The shaft is 9 m long and 7 m wide. The median whorl is circular, broad, flat and horizontally arranged, 46 m in diameter, being the largest of the four whorls. The median whorl is divided into three distinct segments, each possessing eight denticulate margins or spines. The subsidiary whorl is slanted upwards and is situated close to the apical whorl. The subsidiary whorl is divided into three distinct segments with seven to eight denticulate margins. The spines of the apical whorl are the smallest, slanted upwards ending in a crown­like tuft of acute spined projections, 54 (50–58) m, n=20.

Substratum, depth range and ecology. Found on horizontal rocky substrate or under rocky overhangs, together with coral, bryozoans and other sponges. Depth range 46–1500 m

Geographic distribution ( Fig. 2 ). Rio de la Plata, Argentina; Antarctica

Remarks. Ridley and Dendy (1887) described this species as being massive, attached at the base with numerous convex upper surface structures and conical processes. The convex structures they referred to are the mammiform areolate porefields and the conical processes the volcano­shape oscules. Ridley and Dendy (1887) identified about 10 specimens of this species that was collected on the “Challenger” expedition but all were in poor conditions. They remark that the anisodiscorhabd microsclere is the most characteristic feature of this species. The specimen identified by Burton (1932) (BMNH 1928.2.15.823a) (Discovery expedition), and a few BMHN specimens from the Mawson Antarctic Expedition identified as L. lendenfeldi are considered specimens of L. brevis based on the structure of the discorhabd and spicule dimensions (see Table 2, 3). Lévi’s (1993) specimen (MNHN D.CL. 3549) from the deeper waters off New Caledonia, described as L. brevis , were re­examined and compared with both the Holotype species of L. palmata Lévi and L. brevis Ridley and Dendy , and were not conspecific with either species, although they appear to be related in some of their features. The former material is described below as a new species, L. novaecaledoniae sp. nov..

The validity of Latrunculia lendenfeldi Hentschel was resolved in that the type species (ZMB 4812) is a synonym of L. basilis , but many voucher specimens could be considered either specimens of L. bocagei , L. basilis or L. brevis ( Table 2, 3). Bergquist (1968), considered L. antarctica to be synonymous with L. brevis , a view currently disputed by the present authors (see remarks for L. basilis and L. spinispiraefera ).

Bergquist (1968) also described some specimens collected off Three Kings ( New Zealand) as L. brevis (sensu Bergquist 1968: 17–19) , a view that was contested by Alvarez et al. (2002). Alvarez et al. (2002) found that the genus Latrunculia in New Zealand is represented by at least eight different species and that the two colour morphs (green and brown specimens) occurring off the Three kings Islands are undoubtedly two different species ( L. kaakaariki and L. duckworthi ) and separate from L. brevis . Based on the locality and colour morph of the specimen described by Bergquist (1968), it can be concluded that it is a specimen of L. duckworthi Alvarez et al., 2002 . The Cape Brett specimens ( Bergquist 1968) are currently considered conspecific with L. procumbens described by Alvarez et al. 2002 (see below). The synonymy of L. spinispiraefera (sensu Bergquist, 1961) with L. brevis as suggested by Bergquist (1968) is invalid as this specimen is a species of L. triverticillata Alvarez et al. (2002) . Also the synonymy of L. antarctica with L. brevis as suggested by Bergquist (1968) is not considered, because the authors have found that the former species is a junior synonym of L. basilis Ridley and Dendy (1887) . Based on these findings we conclude that L. brevis have a very restricted distribution and is not found to occur in New Zealand and adjacent areas (see Fig. 2 ; Table 2). At present L. bocagei , L. basilis and L. brevis have overlapping distributions in the Antarctic regions and South Atlantic.

Figures

FIGURE 2. Worldwide distributions of Latrunculia (Latrunculia) species. Distributions of 1) Latrunculia cratera du Bocage, 2) L. bocagei Ridley and Dendy, 3) L. apicalis Ridley and Dendy, 4) L. biformis Kirkpatrick, 5) Latrunculia basilis Kirkpatrick, 6) L. brevis Ridley and Dendy, 7) Latrunculia palmata Lévi, 8) Latrunculia multirotalis Topsent, 9) Latrunculia crenulata Lévi, 10) Latrunculia ikematsui Tanita, 11) Latrunculia oxydiscorhabda Alvarez et al., 12) Latrunculia triverticillata Alvarez et al., 13) Latrunculia fiordensis Alvarez et al., 14) Latrunculia novaecaledoniae sp. nov.

FIGURE 4. Photomicrographs of choanosomal architectures: A. L. bocagei Ridley and Dendy 1886; B. Latrunculia apicalis Ridley and Dendy 1886; C. Latrunculia biformis Kirkpatrick 1908; D. Latrunculia basilis Kirkpatrick 1908; E. Latrunculia brevis Ridley and Dendy 1887; F. Latrunculia multirotalis Topsent 1905.

FIGURE 5. Photomicrographs of choanosomal architectures: A. Latrunculia ikematsui Tanita 1968; B. Latrunculia oxydiscorhabda Alvarez et al. 2002; C. Latrunculia triverticillata Alvarez et al. 2002; D. Latrunculia austini sp. nov.; E. Latrunculia citharistae Vacelet 1969; F. Latrunculia purpurea Carter 1881.