Anchialine cave-dwelling sponge fauna (Porifera) from La Quebrada, Mexico with the description of the first Mexican stygobiont sponges Author Gómez, Patricia Instituto de Ciencias del Mar y Limnología, Unidad Académica Ecología y Biodiversidad Acuática, Universidad Nacional Autónoma de México, Cd. Universitaria, CDMX México. C. P. 04510. Author Calderón-Gutiérrez, Fernando Department of Marine Biology, Texas A & M University at Galveston, Galveston, Texas, U. S. A. text Zootaxa 2020 2020-06-25 4803 1 125 151 journal article 10.11646/zootaxa.4803.1.7 1175-5326 3908066 3D8AE62D-7C4D-4E95-A56E-5CE441255E5E Calyx maya sp. nov. Fig. 3 Synonymy and other records. Dendroxea sp. Calderón-Gutiérrez et al. 2018 :S1 Table. Material examined. HOLOTYPE CNPGG‒1630, Cenote S-1, La Quebrada anchialine cave, Cozumel , Quin- tana Roo , Mexico ( 20°26’16.75’’N , 86°59’47.44’’W ). Depth 5.6 m , October 25, 2015 ; coll. F. Calderón-Gutiérrez and G. Yáñez. TABLE I . Comparative data of Haliclona ( Reniera ) species reported from the Caribbean. All the range of morphological variants for each species given by different authors. The quoted colors refer to live sponges.

Species	Locality	Spiculation µm	External morphology	Reference data
H . ( R .) stygobia sp. nov.		Cozumel Island, anchialine cave habitat	Oxeas, some strongylotes 80‒130 × 2.6‒3	Sub-globular, translucent white color	Present work
H . ( R .) implexiformis ( Hechtel, 1965 )		Throughout Caribbean, mangrove, coral reefs, and reef caves	Strongylotes to oxeas: 95‒182 × 3‒10	Thick cushions with oscular volcanic-shaped growths, pinkish violet, bluish purple, cream color	Hechtel 1965 , van Soest 1980 , De Weerdt 2000 , Rützler et al . 2014
H . ( R .) manglaris Alcolado, 1984		Throughout Caribbean, mangrove habitat	Oxeas fusiform: 70‒150 × 2‒6	Encrusting with rope-like processes, green, turquoise or brown color	Alcolado 1984 , De Weerdt 2000 , Rützler et al . 2014
H. (R.) mucifibrosa De Weerdt et al., 1991		Throughout Caribbean, mangrove and reef habitats	Oxeas 186‒270 × 7‒15	Massive base from which arise truncated, thick walled tubes, grayish purple or blue color	De Weerdt et al . 1991 , De Weerdt 2000 , Rützler et al . 2014
H.	(R.) portroyalensis Jackson et al., 2006	Jamaica, mangrove habitat	Oxeas hastate 153‒209 × 6‒8.7	Digitate with slight swollen areas, purple color	Jackson et al . 2006
H. (R.) ruetzleri De Weer- dt, 2000		Belize, mangrove habitat	De Weerdt, 2000
H. (R.) strongylophora Lehnert & van Soest, 1996		Jamaica, deep fore-reef habitat	Strongyles 150‒ 200 × 4‒10	Encrusting, dark brown color	Lehnert & Van Soest 1996
H. (R.) tubifera ( George & Wilson, 1919 )		Throughout Caribbean, mangrove, coral reefs, and reef caves	Oxeas hastate: 104‒171 × 2‒9.5	Thinly creeping branches or cushion-shaped base, with elevated small oscular tubes, gray color	George & Wilson 1919 , Van Soest 1980 , De Weerdt 2000

Description. It is a delicate branching sponge, comprised by two thinly twigs 11 cm long, and each up to 2 mm in diameter, anastomosed at the middle. A basal plate that supports the body is lacking. Color yellowish-white in vivo with a transparent dermal layer ( Fig. 3a ), the color fades when in alcohol. Surface conulose-looking, consisting of protruding three to four aligned spicules, reaching up to 1 mm outside the surface, the same covered by a delicate dermis. Several scattered oscules up to 1 mm in diameter ( Fig. 3b ). Consistency compressible and soft. Skeleton. ( Fig. 3 b-c) The ectosomal skeleton is a tangential unispicular layer of oxeas. The choanosomal skeleton is composed by a central longitudinal tract running along the twig. From this axial tract departs an ill-defined unispicular reticulation tending to isodyctial, (forming triangular to rectangular meshes), that also connects to thinner longitudinal multispicular tracts (up to 33.4 µm in diameter) parallel to surface. Many scattered spicules are in between. Collagenous matrix in a relatively low density. FIGURE 3. Calyx maya sp. nov. a) Holotype CNPGG‒1630 (ethanol); b) ectosome (tangential section, LM); c) skeleton, conule-type (arrows) with 3-4 aligned megascleres (longitudinal section, LM); d) oxea spicules (LM); e) strongyle spicules (LM). Spicules. ( Fig. 3 d-e) Oxeas hastate, straight and slightly curved, with both conical and telescoped ends, 171.6‒ 215 × 2.8‒7 µm . A second category of oxeas is a thinly fusiform oxea, 110‒179.6 × 1.5‒4.4 µm . Strongyles in lesser number, straight to slightly curved also, 106‒210 × 7.5‒9 µm ( Fig. 3e ). Frequent swellings or tubercles occur at the middle part of the shaft, as much of strongyles as of the thinner oxeas. Etymology. The species name refers to the Maya civilization that settled in this area. Geographic distribution. Only known from the type locality. Ecology. This is a stygobite species, living at 5.6 m depth. This is the first record of the genus Calyx in anchialine caves. Apart from this, no individuals fell inside the transects of the quantitative survey, indicating a low population size ( Calderón-Gutiérrez et al. 2018 as Dendoxea sp.). Remarks. According to Desqueyroux-Faúndez & Valentine’s (2002) definition of the genus, Calyx maya sp. nov. agrees well enough with it. The new species only differs for having a single unispicular layer in the ectosomal skeleton instead of a multi-layer as diagnosed in the genus, owing most probably to the small size and highly delicate branched growth form. The unispicular layer could be an adaptation to the low food availability in the cave environment. Calyx maya sp. nov. is distinguished from the two Tropical Western Atlantic Calyx species, by the presence of its thinly branching habit, a single unispicular layer in the ectosomal skeleton, its variable shaped oxeas from hastate, fusiform, through stair-stepped to strongyle. Besides, a good percentage of spicules of the new species have a tuberous centrotylote on the oxeas, which is absent in both C. podatypa (de Laubenfels 1934 as Haliclona ) and C. magnoculata van Soest et al . 2014 . C. podatypa is characterized by a choanosomal sub-rectangular reticulation containing multispicular tracts, and among these many interstitial spicules that make vague isodictyal reticulations; along with its massive body, a denser ectosomal skeleton, key shaped oscules, and smaller spicule sizes, 90‒119 × 2‒4 µm . Van Soest (2017) re-measured the holotype spicules of C. podatypa USNM 22305, uniform in size and shape, and curved thin oxeas, 117‒133‒144 × 2.5‒3.8‒ 5 µm , still different from our new species. C. magnoculata is characterized by its massively encrusting growth form, a dense multilayered crust of intercrossing spicules, and mostly, an isotropic-confused spicule mass at the choanosome, as well as slightly larger spicules (141‒264 × 6‒13 µm ).