Clathria (Thalysias) virgultosa (Lamarck, 1814)

Gómez, Patricia, 2014, The genus Clathria from the Gulf of Mexico and Mexican Caribbean, with redescription and resurrection of Clathria carteri (Poecilosclerida: Microcionidae), Zootaxa 3790 (1), pp. 51-85 : 74-79

Clathria (Thalysias) virgultosa (Lamarck, 1814)

( Fig.17–19 , 20 F, Tab. 6)

Spongia virgultosa Lamarck, 1814 .

Tenacia clathrata Schmidt, 1870:56 , Wilson 1902:397. Clathria copiosa Topsent, 1889:40 .

Clathria jugosa Wilson, 1902:37 .

Thalysias juniperina sensu de Laubenfels 1936a:105, Wiedenmayer 1977:142. Microciona prolifera sensu Green 1977:93 .

Rhaphidophlus juniperinus sensu van Soest 1984:109. Clathria (Thalysias) virgultosa sensu Hooper 1996:411 , Gómez 2007:58.

Material examined. CNPGG –040 Blanquilla reef Veracruz 19º12’55”N 96º6’W, 25/V/1966 (as Microciona prolifera ; Green 1977) bushy habit 14–15 m depth. CNPGG –205 Puerto Morelos, Quintana Roo 20º48’N 86º51’W, 25/IV/1979, 10 m depth, incrusting habit, red alive. CNPGG –240 Puerto Morelos, Quintana Roo 20º48’N 86º51’W, 24/IV/1992, incrusting habit. CNPGG –268 Punta Mocambo, Veracruz 19º9’18”N 96º5’25”W, 2/VII/ 1989, 5 m depth, windward, bushy habit, orange alive. CNPGG –498 Isla Verde Veracruz 19º12’3.1”N 96º3’58”, 25/VII/1987, 2 m depth, incrusting habit, red alive. CNPGG –933 Campeche 19º45’12”N 91º46’18”W, 6/IV/1983, 47 m depth, bushy habit, limestone bottom. CNPGG –1174 Boca Paila, Quintana Roo, 20º0’N 87º28’W, 24/IV/ 1992 incrusting habit, red alive. CNPGG –1179 Ingleses Cay Campeche Bank 21º47’5.18”N 91º59’58.59”W, 13/ XI/2006, 15 m depth, flabellate habit, red alive. CNPGG –1182 Alacranes reef Yucatan 22º23’17.9”N 89º42’8.8”W, 5/VIII/2009 bushy habit, red alive. CNPGG –1184 Yucatan Channel 21º49.6’N 86º48.4’W 25/IV/1985, bushy habit at 30 m depth, sand bottom. CNPGG –1193 Yucatan Channel 23º22.8’N 87º46.3’W, 30/IV/1985, bushy habit 104 m depth. CNPGG –1194 Blanquilla reef Veracruz 19º12’N 96º6’W, 18/V/1979. CNPGG –1200 Alacranes reef Yucatan 22º22’01.4”N 89º40’30.4”W, 3/VIII/2009, encrusting habit. CNPGG –1250 Tampico, Tamaulipas 22º16’37.2”N 97º46’39.59”W, 5/VI/1981, bushy habit 24 m depth. CNPGG –1436 Alacranes reef 22°23’12.89”N 89°40'44.72"W, 25/II/2012, 12 m depth. CNPGG –1437 Alacranes reef 22°23’38.89”N 89° 40’0.90”W, 26/II/2012, 15m depth.

Additional material examined. Microciona microchela Hechtel (1965) holotype YPM 5040 Rasta’s Wreck, Jamaica, May 24, 1961; paratype USNM 24498 Jun/24/1961 Jamaica.

Description. Two morphotypes characterize the present species, an incrusting, and a bushy habit, with the latter predominant. From a small basal plate arise several convoluted branches giving a range of bushy shapes, some samples with little free branchlets on top, others with single and irregular branches fused laterally, sometimes making a trellis of branches or a coalescence of branches in a flabellate outline. The total height is 8.5–28 cm, widest extension 6.5–20 cm, single branches 5–10 mm in diameter. Samples may have a basal plate of adhesion or not: the latter case can grow up directly from the substratum; the former case grows like a low stem up to 2.5 cm high, 1.5–3 cm wide. Incrusting sponges are 10 cm 2 by 5 mm high including protruding ridges. The surface is rugose or bearing irregular ridges, being microhispid all over, but soft to the touch. Commonly red in vivo or occasionally orangey-red, it is pale yellow in spirit; consistency slightly compressible, resilient. No oscula were seen.

Skeleton. The ectosome is a thin layer of auxiliary styles in tufts, with points directed outwards ( Fig. 18 A), with scattered isochelae intermingled; this layer is covered by a delicate translucent whitish dermis which is adhered to the wall and lost when taken out of the water. The choanosomal skeleton is an irregular accretive reticulation of amber fibers 40–150 µm in diameter cored by up to seven styles and echinated acanthostyles at the same time, profusely echinated in the deep choanosome, some flat fibers resembling plates enclose acanthostyles while others just echinate the edge; all fibers are interconnected by uncored thinner ones or one spicule cored. In addition, abundant spicules are strewn in confusion throughout the mesohyl ( Fig. 18 , B).

Spicules. ( Fig. 19 A–I) Auxiliary thin styles in two size categories with smooth and microspined heads: I, 70.2–312 × 1–5.4 µm; II, 101.4–361 × 2.3–11 µm; thick smooth styles III, main megascleres 93.6–340 × 5.2–25 µm, acanthostyles strongly spined mostly at the ends of the shaft, and smooth in the middle 28.6–80.6 × 1.3–12.5 µm, palmate isochelae 8.3–18.3 µm, micro-palmate isochelae 3.3–7.9 µm, oxhorn toxas 16–96.2 × less than one µm, micro-toxa 3.3–16 µm, and rhaphidiform toxa 52.5–400 × less than one µm (Measurements in Table 6).

Remarks. Two morphotypes are evident in C. (T.) virgultosa , the most common being bushy-ramose and the least common encrusting. The different morphs are represented in the material studied and conform to C. (T.) virgultosa in all traits (shape, color, skeletal arrangement, and size and geometry of spiculation). All have a peculiar acanthostyle markedly spined on distal parts, as also described in the literature. Acanthostyles with both heavy spination and small spination are exhibited in any given sample, but necessarily they are spined on distal parts; either for incrusting or bushy habit. This acanthostyle is markedly different from those of other Clathria (Thalysias) species even of other West Indies Clathria .

Smaller microscleres, even difficult to see under light microscopy, were encountered within every specimen in the present material, whether in bushy or in encrusting habit. These are considered a second category of palmate isochelae (4.8 µm average length) and a third category of toxa (7.7 µm average length). Both categories of microscleres are markedly different from the regular microscleres, and have a stable presence in different environments. However, they are easily overlooked, because they are so small and thin.

These very small microscleres necessitated a comparison with Microciona microchela (Holotype YPM 5040 and paratype USNM 24498), now corresponding to C. (T.) hechteli Hooper, 1996 , whose minute isochelae and toxas are its distinctive feature, 4–7 µm, and 5–13 µm respectively. However, C. (T.) hechteli is quite different from C. (T.) virgultosa in many other aspects: it is a very thin encrustation (1 mm thick) and rarely is a repent branch attached at several places, and it is pink with orange in vivo. Moreover, its acanthostyles include smaller spines placed all over the shaft and are larger and thinner (49–117 × 5–8 µm) than those of C. (T.) virgultosa . The main style is thinner as well (7.5–10.6 µm in diameter), and above all the skeletal arrangement is fully leptoclathriid and fibro-reticulated for the branched specimen. It differs also in type of environment, being common in shallow water (1.5–2.6 m) near a mangrove-fringed inlet at Rasta’s Wreck, Jamaica. Nevertheless, the two species are certainly closely related.

Microciona prolifera sensu Green (1977) is recorded for La Blanquilla Reef, West side of the Gulf of Mexico, it corresponds to C. (T.) virgultosa in accordance with the examined material. The study area and other records from the GoM warm waters have not yielded any C. (C.) prolifera . The other tropical records of this species need to be re-examined and are expected to belong to a different species (van Soest et al. 2014).

The Clathria (T.) virgultosa holotype could not be located for the purpose of comparison. Nevertheless our interpretation can be confident since our material matches the literature assignments.

Distribution. Campeche, Tampico, Yucatan, Quintana Roo, Veracruz, Mexico. Other locations: Puerto Rico, West Florida, Cuba, Bimini, Curaçao.

Figures

FIGURE 17. Clathria (Thalysias) virgultosa (Lamarck, 1814): A. Bushy habit from Alacranes reef, Yucatan (CNPGG – 1182). B) Irregular and fused branches from Campeche (CNPGG – 933). C. Flabellate habit from Campeche Bank (CNPGG – 1179). D. Incrusting specimen from Veracruz (CNPGG – 205). E. Incrusting specimen from Alacranes reef, Yucatan (CNPGG – 1200). F. Bushy specimen from Veracruz (CNPGG – 268). Scale bars: A, B, C, F, 2 cm; D, E, 1 cm.

FIGURE 18. Clathria (Thalysias) virgultosa (Lamarck, 1814) skeletal arrangement: A. Ectosome formed of auxiliary styles in brushes in an ill-defined layer (upper side). B. Choanosomal skeleton in transverse section showing an irregular accretive reticulation of cored and echinated fibers. Scale bars: A, B, 500 µm.

FIGURE 19. SEM depiction of spicules from Clathria (Thalysias) virgultosa (Lamarck, 1814): A. Thick styles, B. Thin auxiliary styles, C. Echinating acanthostyles three from bushy habit at left, two from incrusting habit to the right. D. Detail of auxiliary style head. E. Micro-isochelae, F. Normal palmate isochelae, G. Micro-toxa, H. oxhorn toxa, I. Rhaphidiform toxa. Scale bars: A, B, I, 50 µm; C, H, 20 µm; D, F, 5 µm; E, 3 µm; G, 5 µm.

FIGURE 20. Just out of water: A. Clathria (Clathria) foliacea Topsent, 1889 (CNPGG – 1358 Madagascar reef, Yucatan, Mexico. B. Clathria (Clathria) carteri Topsent, 1889 (CNPGG – 1366 Bajos de Sisal reef, Campeche Bank, Mexico). C. Clathria (Microciona) echinata (Alcolado, 1984) (CNPGG – 1409 Progreso, Yucatan). D. Clathria (Microciona) spinosa (Alcolado, 1984) (CNPGG − 1186 Madagascar reef Yucatan). In situ: E. Clathria (Thalysias) venosa (Alcolado, 1984) (CNPGG – 1452 Blanquilla reef Veracruz). Just out of water: F. Clathria (Thalysias) virgultosa (Lamarck, 1814) CNPGG – 1179 Campeche Bank. Scale bars A, B, C, D, F, 2 cm; E, 1 cm.