Notes on the Ecology of the Pogonophoran Genus 
Galathealinum Kirkegaard, 1956 
Oluwafeyisola S. Adegoke 1 
The pogonophoran genus Galathealinum 
Kirkegaard, 1956 has a rather wide areal and 
latitudinal range in the northern hemisphere. 
It has been recorded from the Arctic Ocean, 
latitude 69° 32'N (Southward, 1962) to the 
Celebes Sea, about 1° 50' north of the Equator 
(Kirkegaard, 1956). This wide latitudinal 
range makes the genus an exceptionally good 
one for examining the ecological factors which 
control pogonophoran distribution, and one 
would like to know what ecologic factors may 
be found to interpret the wide latitudinal range. 
Four species have been described within the 
genus. The first, Galathealinum hruuni (the 
type species) was described by Kirkegaard 
(1956) from the Celebes Sea in the western 
Pacific. Ivanov (1961) next described G. 
hrachiosum from the Pacific coasts of Canada 
and Oregon. The most northerly known spe- 
cies, G. arcticum was described by Southward 
(1962) from Thetis Bay, Herschell Island, 
north of Yukon, Alaska. The writer recently 
(Adegoke, 1967) described the fourth species, 
G. mexicanum from collections made in the 
Gulf of Tehuantepec, Mexico. The specimens 
from the same region earlier listed as G. 
hruuni (?) by Parker (1963:86) belong to this 
latter species. Apart from these four species, 
Hartman and Barnard (I960) listed the occur- 
rences of a few large-sized fragments (3-4 
mm diameter) of pogonophoran tubes from 
West Cortes, East Cortes, and Long basins, and 
from the San Diego Trough off the coast of 
southern California. These fragments were later 
referred to the genus Galathealinum by Hart- 
man (1961:546). Although specifically inde- 
terminable, these fragments are significant be- 
cause they are the largest reported tubes of 
members of this genus. 
1 Division of Geological Sciences, California Insti- 
tute of Technology, Pasadena, California. Present 
address: Department of Geology, University of Ife, 
Ibadan Branch, Ibadan, Nigeria, West Africa. Manu- 
script received September 29, 1966. 
ACKNOWLEDGMENTS 
The author wishes to thank Professor Heinz 
A. Lowenstam of the California Institute of 
Technology for his critical reading of the manu- 
script and for his helpful suggestions. The 
figures were prepared by Mrs. Ruth Talovich. 
ECOLOGY 
Because the first records of pogonophoran 
species were from great depths it was initially 
assumed that pogonophorans were exclusively 
inhabitants of abyssal and hadal depths (Kirke- 
gaard, 1956:80). Subsequent records (Ivanov, 
1963; Jagersten, 1956; Kirkegaard, 1958; A. 
J. Southward, 1958; E. C. Southward, 1962; 
Southward and Southward, 1958, 1963) of 
pogonophoran species from extremely shallow 
waters (for example, Sihoglinum caulleryi 
Ivanov from 22 m in the Sea of Okhotsk; and 
Galathealimim arcticum Southward from 36 m 
in Thetis Bay, Herschell Island, Yukon, Alaska) 
clearly showed that absolute depth is not neces- 
sarily a limiting factor in pogonophoran ecology. 
It is now known that, although a majority of 
pogonophoran species inhabit abyssal and hadal 
depths, only a few are characteristically confined 
to such habitats (Ivanov, 1963:123-126; 
Southward, 1962:385). Many species are en- 
countered at comparatively shallow depths and 
a few forms are also known to dwell at bathyal 
or even sub-littoral depths. A relatively large 
number, however, thrive in shallow as well as 
in deep waters. Thus, S. caulleryi Ivanov has 
been recorded from depths ranging from 22 m 
in the Sakhalin Gulf to depths of about 8,164 
m in the Kuril-Kamchatka Trench (Ivanov, 
1963:221). According to D. B. Carlisle (see 
Ivanov, 1963:123), this is the greatest known 
bathymetric range for any known species of 
marine organism. 
In the light of these presently known depth 
distributions, Kirkegaard (1958:1087) and 
558 
