A guide to the deep-water sponges of - NMFS Scientific Publications ...

112 Professional Paper NMFS 12
92. Mycale (Mycale) tylota Koltun, 1958
Description. This sponge is massive with a smooth
but convoluted surface. Circular oscula are on conical
elevations. Consistency is inelastic and very easily torn.
Diameter is to 10 cm. Color in life is yellow to golden
brown.
Skeletal structure. There is a thick ectosomal crust of
styles to tylotes that are scattered without obvious orientation
and tangentially arranged with many microscleres
in between. Choanosomal pauci- to polyspicular tracts
are in triangular meshes with masses of sigmas in between.
Rosettes of large anisochelae are less abundant.
There are ectosomal styles to tylotes (415–570 × 10–16
µm), choanosomal styles (670–890 × 15–25 µm), large
anisochelae (95–112 µm), small anisochelae (15–35
µm), large sigmas (82–105 µm), small sigmas (25–35
µm), and rhaphides (70–110 µm).
Zoogeographic distribution. Locally common. In
Alaska – central Aleutian Islands. Elsewhere – southern
Kuril Strait.
Habitat. In Alaska – attached to cobbles and pebbles
at depths between 135 and 175 m. Elsewhere – reported
at depths between 73 and 181 m.
Photos. 1) Specimen collected at a depth of 172 m
in the central Aleutian Islands. Grid marks are 1 cm 2 .
2) Same specimen as in photo 1 (indicated by the white
arrow) in situ.