Clathria (Clathria) carteri Topsent, 1889

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 : 59-63

Clathria (Clathria) carteri Topsent, 1889

( Figs. 5–8 , 20 B, Tab. 2 )

Clathria carteri Topsent 1889:38 .

Non Clathria (Clathria) foliacea sensu Hooper 1996:173 .

Species status. Despite the inability to find the type material nominated by Topsent (1889) in the Paris Museum, the newly collected material and borrowed specimen of Thalyseurypon foliacea was essential for comparison and characterization of C. (C.) carteri , demonstrating significant differences to resurrect C. carteri . Consequently a neotype is established here based on fresh material and collected from near the type locality.

Neotype (here designated): CNPGG–499 Yucatan Channel 22º23.2’N 87º5.4’W, 23/X/1985, 44 m depth.

Description of neotype. Flabellate bush, supported by a large peduncle. The branches are mostly foliaceous, laterally joined at different levels 17 cm in total height, 9 cm in upper diameter, peduncle 7 cm long and 5 mm thick ( Fig. 5 A). It is dull red in vivo, beige in spirit. Under the microscope it has a micro-hispid surface and neither oscula nor pores were seen. It is slightly pliable. The skeleton is an irregular reticulation not defined in ascending or connective fibers but tending towards axial compression. These fibers are amber colored, 20–80 µm in diameter, sparsely echinated by acanthostyles and cored by thick tylostyles, sometimes uncored. Fiber endings at the surface are crowned by a brush of thick tylostyles with protruding ends. This pattern develops the microhispid nature of the surface (Spicule measurements in Tab. 2 ).

Material examined. USNM 1156281Yucatan Channel 21º55’N 87º10’W, 25/IV/1985. CNPGG –077 Yucatan Channel 22º2.4’N 87º2.5’W, 25/IV/1985, sand bottom, 35 m depth. CNPGG –099 Yucatan Channel 21º55’N 87º10’W, 25/IV/1985, sand bottom 23 m depth; CNPGG –1175 Xahuayxol, Quintana Roo 18º30’N 87º45’W, 24/ IV/1992. CNPGG –1366 Bajos de Sisal reef, Campeche Bank 21º26’20.9”N 90º16’58.9”W, 4/VI/2012, 18 m depth.

Description. Generally a bushy habit with flabellate branches arising from a slender or thick basal stalk; in one case the branches are slender with digitiform limbs along the branch. Two samples were covered by anthozoans ( Fig. 5 A–D). The size range is 8–15 cm in height, 6–9 cm in upper diameter; the basal stalk is 30–70 mm long and 5–20 mm thick. The smallest specimen looks like a labyrinth ( Fig. 5 C) 3 cm in height, 5 cm wide. The consistency is slightly pliable, surface microhispid with no visible oscula or pores, its color when alive is dull red, dull yellow in spirit.

Skeleton. ( Fig. 5 E–F) A strongly developed arborescent reticulum of amber spongin fibers axially compressed, fibers well differentiated in primary ascending or secondary connective components. Primaries are cored by tylostyles and sparsely echinated by acanthostyles and tylostyles as well; in some places they are uncored. Ends of fibers are ornamented with a plumose end of thick tylostyles in diverse quantity, which project beyond the surface to producing a microhispid surface. Ascending fibers measure 60–150 µm, in some places tending to a lamina or a plate 100–160 µm wide, the secondary fibers are mostly uncored and virtually unechinated, 19–60 µm in diameter. Meshes are round to oval, sometimes in an irregular pattern, 50–250 µm. The dermal layer consists of auxiliary styles tangentially placed among abundant microscleres delineating the surface.

FIGURE 6. SEM depiction of spicules from Clathria (Clathria) carteri Topsent, 1889 : A. Tylostyles, main megascleres. A1- A2. Detail of different heads showing the smooth and microspined condition. B-B1. Transitional to tylostyles and detail of head. C-C1. Auxiliary styles and microspined head. D. Acanthostyle minutely spined. D1. Detail of acanthostyle head. E. Palmate isochelae. F. Toxa in two size categories. G. Spiculation general view. Scale bars: A, B, 60 µm; A1, B1, 5 µm; A2, 25 µm; C, 50 µm; C1, 15 µm; D, 20 µm; D1, 10 µm; F, F1, 40 µm.

Spicules. (Fig. 6A–G) Auxiliary subtylostyles straight and slender, some with faintly swollen heads, both smooth and/or microspined head 96.2–392 × 1–6.2 µm. Thick tylostyles straight or slightly bent, with smooth or microspined heads 119.6–410 × 5.2–28.6 µm. Acanthostyles are minutely spined all over, at times faintly spined, with tiny spines on head 52–120 × 2–10.4 µm. Palmate isochelae never twisted 12.2–18.2 µm. Wide oxhorn toxas, others not so, in two size categories that overlap: 20.8–222 µm and less than one micron to 5.2 µm (Measurements in Tab. 2 ).

Remarks. Despite the similarities in habit and the red color when alive, C. (C.) carteri is resurrected from the captive synonym of C. (C.) foliacea , taking into account two main features: skeleton and spiculation. This arises from examination of fresh material from the type locality, which was compared with fresh material in the same locality as C. (C.) foliacea .

In addition to skeletal and spicular differences, there are also some external morphological differences between the two species, not stated in Topsent's work, but fortunately a drawing of the complete morphology of C. (C.) carteri exists in Topsent (1889) which formed the basis in the selection of the neotype here. The morphological characterization of C. (C.) carteri relies also on the analysis of the several studied specimens, which distinguishes it from C. (C.) foliacea by: 1) axially compressed skeletal arrangement as well as the more echinated spicules versus profusely plumose reticulation and scattered echination in C. (C.) foliacea ; 2) a thin fiber versus thicker fiber diameter in C. (C.) foliacea ; 3) main megascleres with a finely spined or smooth head versus a tuberculated head on main megascleres of C. (C.) foliacea ; 4) finely spined acanthostyles very often faintly and scarcely spined versus tuberculate acanthostyle head in C. (C.) foliacea , 5) different geometry on toxas, with a thick shaft in C. (C.) carteri versus thin shaft in C. (C.) foliacea ; and 6) a larger typical palmate chela versus a twisted chela up to 11.7 µm in C. (C.) foliacea . Moreover, a one-way ANOVA showed significant differences in spiculae between C. (C.) foliacea and C. (C.) carteri with values of F=1086.8 (P= <0.00001) for length and F=80.3 (P=0.00003) for width, which better delimit the different populations ( Fig. 7–8 ).

This is the first taxonomic description of Clathria (C.) carteri since the original description, strengthened by the statistical analysis of spicule measurements. Some evidence shows that intraspecific variability can be significant for a given taxon, and spicule size-ranges can span across several closely related taxa which were otherwise erected solely on that basis of megasclere and microsclere dimensions; but so far only few studies have investigated the statistical variability of spicule size for comparison between species ( Hooper 1996). According to Hooper et al. (1990) “Two sibling species of Clathria could not be reliably distinguished by their absolute spicule sizes, and only statistical comparisons between these species were of any value in this regard”. Thus spicule dimensions used as diagnostic characteristic are of most significance at the species level of classification and consequently is generally comparative rather than absolute ( Hooper 1996). Molecular studies currently in use could furnish further scientific validity, but morphological studies appear to provide sufficient certainty in this particular case.

It can be concluded that the two entities discussed here, C. (C.) foliacea and C. (C.) carteri , are not conspecific.

Distribution. There are no records cited for Clathria (C.) carteri . The only record known is from the type locality Campeche in 1889. The present study has widened its distribution to Yucatan and Quintana Roo, Mexico.

Figures

FIGURE 5. Morphs of Clathria (Clathria) carteri Topsent, 1889: A. NEOTYPE CNPGG – 499 Yucatan Channel. B. CNPGG – 077 Yucatan Channel. C. CNPGG – 1175 Quintana Roo. D. CNPGG – 099 Yucatan Channel. E. Detail of skeletal arrangement of Neotype. F. General skeletal arrangement. Scale bars: A, C, D, 2 cm; B, 1 cm; E, 200 µm; F, 150 µm.

FIGURE 7. Significant differences in length of style I, style II, acanthostyle, isochelae and toxa I between C. (C.) carteri and C. (C.) foliacea. One-way ANOVA, F = 1086.8 P = <0.00001.

FIGURE 8. Significant differences in width of style I, style II, and acanthostyle between C. (C.) carteri and C. (C.) foliacea. One-way ANOVA, F = 80.3 P = 0.00003.

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.

Tables

TABLE 2. Spicule micrometries, distribution / depth (in meters) of Clathria (Clathria) carteri Topsent 1889. Measurements are in µm, mean values are in bold, measurement number n = 30. YUC, Yucatan Channel; Q. R., Quintana Roo; n. r., not recorded; (♠ Neotype designated).

Specimen	Location	Subtylostyle	Tyloestyle	Acanthostyle	Toxa I	Toxa II	Isochelae
CNPGG	YUC/	142– 249.4 –360/	148.2– 258–410/	65– 85.8 –104/	28.6– 60 –110/	96.4– 127.1– 177/	12.2– 14.8 –16.9
499 ♠	44	1.8– 3.20 –5.2	7.8– 13.1– 18.7	4.6– 7 –10.4	<1–1	2– 3.4 –5.2
CNPGG	YUC/	127– 211 –330/	140– 239.4 –390/	65– 87.4 –120/	27.3– 56 –91/	98.8– 135.5 –213/	12.4– 14.2 –15.6
77	20	1.5– 3.1 –4.9	5.2– 14.3 –28.6	4.6– 6.64 –10.4	1.2– 1.7 –2	2– 2.7 –3.9
CNPGG	YUC/	96.2– 190 –392/	130– 254.6 –397/	54.6– 82.5 –111.8/	28.6– 54 –94/	25.4– 118 –222/	12.2– 14.6 –18.2
99	23	1.5– 2.8 –6	6.7– 14.1 –25	2– 6.1 –9	<1	1.8– 2.9 –5.2
CNPGG	Q.R./	127– 220.4 –377/	119.6– 235 –390/	52– 78.7 –91/	20.8– 57.8 –90/	85– 107.9 –148.9/	13– 14.9 –18.2
1175	n.r.	1– 2.7 –6.2	5.2– 10.8 –18	3.1– 5 –7.8	<1	1.5– 2.1 –2.8
Average		218/2.94	245.4/12.8	83.6/6.1	56.96/1.7	120/2.8	14.6