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

2 Professional Paper NMFS 12
larly fragile and are often highly fragmented at the time
of collection.
Current practice aboard commercial fishing vessels
in Alaska (note that not all vessels are required to have
fishery observers onboard) calls for tasked personnel
to identify sponge bycatch to the lowest practical taxa
– essentially to Phylum Porifera. The Alaska Fisheries
Science Center’s Fisheries Monitoring and Analysis
Division (FMA) maintains all records, including depth
and location data, through its North Pacific Groundfish
Observer Program. The accuracy of those data depends
foremost on the type of fishing gear, but also varies due
to the spatial coverage of the gear (i.e., only start and
end positions and depths are recorded). Specimens are
typically not retained for specific scientific purposes.
Current practice aboard NOAA survey vessels differs
between the two principal surveys. Specimens are
retained for further study upon request, but no formal
program for the collection and preservation of specimens
exists otherwise. The emphasis of both surveys
is to gather information necessary for the sustainable
management of groundfish species. Monitoring the
bycatch of structure-forming invertebrates, such as
sponges, has become more of a priority with recent
emphasis on managing fisheries with an ecosystem approach.
For the NMFS sablefish longline survey, sponges
are only identified to the general level of “unidentified
sponge.” For the NMFS groundfish trawl survey, wet
weight of sponges is recorded either completely or by
subsampling. Collection data are then coded (NMFS
RACE Species Code Book – maintained by the Resource
Assessment and Conservation Engineering Division’s
Groundfish Assessment Program) and entered into a
database. Sponges are identified from a guide that was
developed specifically for the identification of benthic
marine invertebrates collected along Alaska’s upper
continental slope and shelf (Clark 1 ). This guide has
been an important first step toward more adequately
monitoring sponge bycatch, but it is largely incomplete,
contains species that have never been confirmed
to occur in Alaskan waters, and lists some species with
inaccurate taxonomic nomenclature. Clearly there is a
strong need for a guide dedicated to the identification
of Alaskan sponges and a continued effort to properly
identify the sponge fauna collected from the region.
The sponges contained in this guide were collected
principally during two expeditions to the central Aleutian
Islands in 2004: one aboard the RV Velero IV and
the other aboard the RV Roger Revelle. A few additional
sponge specimens were collected during the pioneering
work in the region aboard the RV Velero IV in 2002 and
1 Clark, R. N. 2006. Unpubl. manuscript. Field guide to the
benthic marine invertebrates of Alaska’s shelf and upper slope taken
by NOAA/NMFS/AFSC/RACE Division trawl surveys. 302 p.
2003. The focus of the research supporting the cruises
was on deep-water coral habitat; there was a dedicated
effort to collect sponge fauna for formal identification
only during the RV Velero IV cruise in 2004 and even then
it was of secondary importance. We also include collections
made in the eastern Gulf of Alaska aboard the RV
Velero IV in 2005 and in the Bering Sea Canyons (Pribilof
and Zhemchug) aboard the RV Esperanza in 2007.
We reviewed video footage of the seafloor collected
during 31 dives with the submersible Delta and 13 dives
with the ROV Jason II. A total of approximately 127 km
of seafloor habitat was examined (35 km and 92 km,
respectively) from that video footage for the presence
of sponge fauna, with particular focus on taxa included
in this guide. Habitat information including depth,
substrate, and associated fauna were recorded for
sponge observations, often made from multiple camera
perspectives.
About this guide
This guide contains detailed species descriptions for 112
sponges collected in Alaska, principally in the central
Aleutian Islands. Each species description begins with
the scientific name using classical binominal nomenclature.
The first name (always capitalized) is the genus.
The second name (never capitalized) is the species.
Some species may have a third name (never capitalized)
for designated subspecies. And for some species
a subgenus may have been designated and is placed in
parentheses after the current genus. The name(s) of the
author(s) of the species description (i.e., the person(s)
who described the species) and year of description
follow the scientific name. Parentheses placed around
the author(s) name(s) indicates that there has been an
accepted modification to genus assignment since the
original description. For example, Acanthascus (Rhabdocalyptus)
dawsoni dawsoni (Lambe, 1893) is represented
as Genus (subgenus) species subspecies (Author, year).
Each species description provides information on
1) typical growth form(s), 2) surface morphology, including
the presence and description of oscula, 3) consistency
and texture, 4) known size range or dimensions,
and 5) color in life and under various preservation
methods. These characteristics, when used in conjunction
with a confirmed photograph, can often provide
a fairly accurate identification in the field. Definitive
identification of most species, however, requires careful
examination of the arrangement of microscopic skeletal
structures, particularly the types, sizes, and location of
spicules. Note that the identification of each species
detailed in this guide has been confirmed by examination
of microscopic features. We provide detailed information
on the skeletal structure of each species so