Cliona aff. mucronata Sollas, 1878

Pacheco, Cristian, Carballo, José Luis, Cortés, Jorge, Segovia, Johanna & Trejo, Alejandra, 2018, Excavating sponges from the Pacific of Central America, descriptions and a faunistic record, Zootaxa 4370 (5), pp. 451-491 : 463-465

Cliona aff. mucronata Sollas, 1878

Material examined. CIMAR.BS.SA01, CIMAR.BS.11, CIMAR.BS.19: Bahía Salinas, 16 m. 8.XII.2010, coll. and det. Cristian Pacheco Solano . CIMAR. BS.21, CIMAR.BS.22, CIMAR.BS.23, CIMAR.BS.25, CIMAR.BS.26, CIMAR.BS.50, CIMAR.BS.52, CIMAR.BS.53: Bahía Salinas, 8 to 20 m, 3.III.2011, coll. and det. Cristian Pacheco Solano . CIMAR. CU.05, CIMAR.CU.09(II), CIMAR.CU.09(III), CIMAR.CU.09(IV), CIMAR.CU.09(V), CIMAR.CU.05, CIMAR.CU.08, CIMAR.CU.14: Bahía Culebra, 8 to 15 m. 21.III.2011, coll. and det. Cristian Pacheco Solano . CIMAR. CU.120, CIMAR.CU.123, CIMAR.CU.127, CIMAR.CU.200, CIMAR.CU.201, CIMAR.CU.210/1, CIMAR.CU.191(I), CIMAR.CU.191(II), CIMAR.CU.191(III), CIMAR.CU.191(IV), CIMAR.CU.191(V): Bahía Culebra, 8 to 15 m, 18.VI.2011, coll. and det. Cristian Pacheco Solano . CIMAR. IC.21, CIMAR.IC.32: Isla del Caño , 10 m, 12. II.2011, coll. and det. Cristian Pacheco Solano . CIMAR.IT.01: Isla Taboga , Panama, 1 m, 10.I.2012, coll. and det. Cristian Pacheco Solano .

External morphology. Endolithic sponge in alpha morphology. Circular papillae with average diameter of 330 µm. Live color orange.

Excavation. Multicamerate erosion. Chambers with average diameter of 1 mm and occasionally fused. Comparatively smooth erosion scars with sharp edges, between 24 and 66 µm in diameter, smallest scars at passages of exploratory threads ( Fig. 13 ).

Spicules. Megascleres as tylostyles ( Fig. 14 ). Two types of tylostyles: I. larger and slimmer type slightly curved in upper half, tyles usually subterminal, and II. shorter ensiform to mucronate type, slightly curved or straight, tyles also subterminal. No microscleres observed. Spicule dimensions for tylostyle I: 92.5–247 µm (x̅ =132.9, σ=23.9) x 1.0–10.0 µm (x̅ =2.9, σ=0.9). Spicule dimensions for tylostyle II: 27.5–115 µm (x̅ =78.7, σ=11.1) x 1 –17.5 µm (x̅ =4.4, σ=1.6).

Ecology. Excavating dead and living coral Pavona sp. Furthermore eroding dead P. lobata and Pocillopora sp. Also found excavating mollusk shells. Occurring between 1 and 20 m depth.

Distribution and previous records. Cliona mucronata was originally described by Sollas (1878) excavating the calcareous skeleton of the soft coral Isis sp., but the sample site was not specified. Later accounts for this species were usually for the Indo-Pacific ( Vacelet & Vasseur 1971; Thomas 1972; Desqueyroux-Faúndez 1981; Calcinai et al. 2000). Later records became available from other locations, placing the species at the shores of mainland Mexico, the Revillagigedo Archipelago, Mexico and the Caribbean Sea ( Bautista-Guerrero et al. 2006; Carballo et al. 2008a, 2008b; Rützler et al. 2014; Vega 2012). The spicule morphology in some of these more recent accounts, however, suggested that some records may have been different from C. mucronata sensu stricto, but may be in better congruence with our material. Like Vega (2012), this study reports C. aff. mucronata from Costa Rica and Panama ( Fig. 15 ).

Remarks. C. mucronata is a well-established, easy to identify and fully accepted clionaid species with a wide distributional range ( Soest et al. 2016), even if the type location remains unknown ( Sollas 1878; see Schönberg et al. 2017). However, due to spicule characters some recent reports under this name may not be regarded as conspecific and were partly conditioned with the insertion of “cf.”, indicating an uncertain identification ( Vacelet & Vasseur 1971; Bautista-Guerrero et al. 2006; Carballo et al. 2008a, 2008b; Rützler et al. 2014; Vega 2012). In typical representatives of the Indo-Pacific spirasters were reported (e.g. Thomas 1972; Calcinai et al. 2000), but not in the above accounts or from our samples. Moreover, the shape of the shorter tylostyle appears to differ between some of these publications and implies the existence of an unresolved species complex. Due to these potentional differences, we consider our specimens as being in close affinity to, but more likely different from C. mucronata in the strict sense, and we used the qualification “aff.”.

Our specimen characters appear to differ from Sollas’ (1878) account, but match those of the previously published Mexican samples ( Bautista-Guerrero et al. 2006). Exact matching of material will be difficult, but should be attempted due to the common occurrence of this species in the ETP.

Figures

FIGURE 13. Cliona aff.mucronata bioerosion. A) Erosion chamber (arrow) and B) erosion scars.

FIGURE 14. Spicules of Cliona aff. mucronata: A) spicular variation of large tylostyles and one short tylostyle, B) short, ensiform tylostyles, with two immature stages.

FIGURE15. Distribution of Cliona aff.mucronata in the study area.