Myxilla (Burtonanchora), 1936

Hajdu, Eduardo, Desqueyroux-Faúndez, Ruth, Carvalho, Mariana De Souza, Lôbo-Hajdu, Gisele & Willenz, Philippe, 2013, Twelve new Demospongiae (Porifera) from Chilean fjords, with remarks upon sponge-derived biogeographic compartments in the SE Pacific, Zootaxa 3744 (1), pp. 1-64 : 54

Identification key for Myxilla (Burtonanchora)

1a. Microscleres include sigmas............................................................................. 2

1b. Microscleres do not include sigmas....................................................................... 9

2a. Sigmas in two size categories, the larger ones mostly> 70 µm and frequently>100 µm................... M. (B.) magna

2b. Sigmas in one or two size categories, the larger ones mostly <70 µm, never>100 µm............................... 3

3a. Choanosomal megascleres maybe> 600 µm in length, ectosomal ca. 350 µm in length.................. M. (B.) hastata

3b. Choanosomal megascleres <600 µm in length, ectosomal <300 µm in length.................................... 4

4a. Only one category each of anchorates and sigmas........................................................... 5

4b. Two categories each of anchorates and sigmas............................................................. 7

5a. Choanosomal megascleres> 400 µm in length.............................................. M. (B.) asymmetrica

5b. Choanosomal megascleres <300 µm in length............................................................. 6

6a. Choanosomal megascleres <150 µm in length, ectosomal megascleres <5 µm thick, anchorate isochelae <20 µm long............................................................................................. M. (B.) gracilis

6b. Choanosomal megascleres> 150 µm in length, ectosomal megascleres> 5 µm thick, anchorate isochelae> 30 µm long............................................................................................ M. (B.) lacunosa

7a. Smaller anchorate isochelae ca. 10 µm in length................................................ M. (B.) crucifera

7b. Smaller anchorate isochelae> 15 µm in length............................................................. 8

8a. Choanosomal megascleres> 300 µm in length, tornotes maybe> 200 µm in length, larger sigmas up to 50 µm in length.......................................................................................... M. (B.) sigmatifera

8b. Choanosomal megascleres <300 µm in length, tornotes <200 µm in length, larger sigmas up to 40 µm in length............................................................................................... M. (B.) myxilloides

9a. Choanosomal megascleres> 600 µm in length, anchorate isochelae often> 100 µm in length............ M. (B.) lissostyla

9b. Choanosomal megascleres <550 µm in length, anchorate isochelae <75 µm in length............................. 10

10a. Choanosomal megascleres often> 400 µm in length, anchorate isochelae in a single size category.................... 11

10b. Choanosomal megascleres <400 µm in length, anchorate isochelae in two size categories................. M. (B) ponceti

11a. Tornotes terminally microspined...................................................... M. (B.) araucana sp. nov.

11b. Tornotes terminally mucronate......................................................................... 12

12a. Sponge club-shaped, stalked, acanthostyles present, raphides absent............................. M. (B.) pedunculata

12b. Sponge cylindrical, acanthostyles absent, raphides present........................................ M. (B.) pistillaris