Melonanchora elliptica

Carter, 1874b

Species Overview

Melonanchora elliptica Carter, 1874b is a yellowish bladder-like deep-water sponge provided with chracteristic short flattened tubercles. It has very characteristic microscleres called melonchelas or sphaerancoras (microscopic examination).

Taxonomic Description

Colour: Yellowish white or whitish grey.
Shape, size, surface and consistency: Globular, with many truncated-flattened surface tubercles. Size up to more than 10 cm in diameter. Surface between tubercles smooth. Pores and oscules are at the flattened end of the tubercles. Consistency of ectosome parchment-like, firm, of interior mass crumbly, fragile.
Spicules: (Melonanchora elliptica spics) Megascleres : Ectosomal tylotes, smooth, slightly anisotylote, fusiform, with smooth heads: 410-620 x 15 µm; choanosomal styles, smooth, curved: 680-860 x 15 µm.
Microscleres : Spatuliferous anchorate chelae in two size classes: 21-28 µm and 47-75 µm; sphaerancoras (or melonchelas melonancora): 54-68 µm.
Skeleton: Ectosomal skeleton a feltwork of tangentially arranged tylotes. Choanosomal skeleton an irregular reticulation of multispicular tracts of styles.
Ecology: 50-1300 m
Distribution: Norway, Sweden, Faroes; Azores, Cape Verde Islands; also recorded from the West Indies but that needs confirmation.
Etymology: The name refers to the elliptical sphaerancoras.
Type specimen information: Natural History Museum, London: BMNH 1882:7:28:54.

Remarks

This is an easily recognizable sponge. A second species of Melonanchora , viz. M . emphysema (Schmidt, 1875) occurs sympatrically, but is not treated here because it is only known from 180 m downwards. It differs from the present species in the absence of styles.
Source: Arndt, 1935