Clathria (Thalysias)

Zea, Sven, Rodríguez, Angélica & Martínez, Ana María, 2014, Taxonomy of Clathria (Thalysias) (Demospongiae: Poecilosclerida: Microcionidae) from the Colombian Caribbean, with description of three new species, Zootaxa 3835 (4), pp. 401-436 : 433-434

Key to the species of Clathria (Thalysias) occurring in the Greater Caribbean

This key assumes that the specimen being keyed has already been identified to the subgenus Thalysias , i.e., having two categories of auxiliary subtylostyles, the smaller ones concentrated towards the surface, forming brushes that support the pinacoderm. This arrangement can be studied mounting in balsam or permount dried or dehydrated thick sections perpendicular and tangential to the surface or just observing a macerate of fresh surface tissue. Following this key with similar species belonging to other subgenera of Clathria may yield unexpected or ambiguous results.

1a. Erect, branching or bushy; branches may be repent or may arise from an extended encrusting base....................(2)

1b. Thinly encrusting (up to 1–2 mm) to thickly encrusting-massive (> 2 mm)........................................(3)

2a. Long (>190 µm) oxeote to rhaphidiform toxa present, in addition to normal, wing-shaped ones. Tissue bright red to orange in life, overlaid by a network of white lines over the canal system.................................... .. C. (T.) virgultosa

2b. Toxa smaller, wing-shaped, accolade and raphidiform. Tissue yellow to orange-yellow in life, overlaid by a transparent mem- brane with whitish lines over canals........................................................ C. (T.) curacaoensis

3a. Thickly encrusting; surface strongly conulose to tuberculate. Tissue bright red to orange in life, overlaid by a network of white lines over the canal system................................................................. C. (T.) virgultosa

3b. Thinly encrusting, surface smooth.......................................................................(4)

4a. Toxa present........................................................................................(5)

4b Toxa absent.........................................................................................(9)

5a. Principal styles with smooth heads (minutely spined at most)..................................................(6)

5b. Principal styles with prominent heads, slightly to strongly rugose, spined or warty................................(12)

6a. Oxeote toxa present...................................................................................(7)

6b. Oxeote toxa absent...................................................................................(8)

7a. Oxeote toxa very long (>500 µm) and stout. Consistency soft. Tissue orange, overlaid by irregular and sparse white lines fol- lowing the canal system...................................................................... C. (T.) oxeota

7b. Oxeote toxa smaller, thin to rhaphidiform. Consistency tougher. Tissue bright red to orange in life, overlaid by a network of white lines over the canal system............................................................ C. (T.) virgultosa

8a. No chelae, only bean-shaped colloscleres. Tissue red............................................ C. (T.) collosclera

8b. Chelae present; no colloscleres. Tissue bright yellow to orange-yellow in life, duller over the star-shaped vein pattern of the canal system and oscules................................................................. C. (T.) curacaoensis

9a. With modified palmate isochelae.......................................................................(10)

9b. Palmate isochela of normal shape. Pinacoderm thick, cellophane-like, whitish to iridescent live, with underlying tissue from orange to brownish................................................................... .. C. (T.) opalina n. sp.

10a. Sigma-like chelae. Live color sulfur yellow in between a transparent star-shaped vein pattern of the canal system and oscules............................................................................... C. (T.) chelosigmoidea n. sp.

10b. Palmate isochelae with enlarged alae and/or ridged shaft.....................................................(11)

11a. Palmate isochelae with a ridged shaft; alae normal. Live color bright red........................... C. (T.) isodictyoides

11b. One category of palmate isochela with enlarged alae and shaft (cleistochelae), the other normal. Live color sulfur yellow in between a transparent star-shaped vein pattern of the canal system and oscules.............. C. (T.) sulfocleistochela n. sp.

12a. Oxeote toxa present, next to normal, wing-shaped ones. Acanthostyles 40–70 µm. Slightly thick (up to 2 mm) and soft. External color pinkish to grayish with a strongly developed star-shaped vein pattern of the canal system and oscules; internal color bright orange............................................................................... C. (T.) venosa

12b. Only normal, wing-shaped toxa present, characteristically recurved. Acanthostyles in a wider range of sizes, 60–180 ìm. Color red to scarlet; canal system little evident......................................................... C. (T.) minuta