**Operation Deep-Scope 2005** lost 7 of 14 dive days due to Hurricane
Katrina and equipment problems. This meant that each of the 5 PIs was
only able to make 3 (Frank, Widder) or 2 (Matz, Marshall, Johnsen)
submersible dives. In spite of this, several significant achievements
came as a result of this expedition, as listed below.

**1) Fluorescence -- Matz**

During the 2005 cruise we were able to make only two submersible dives
equipped for fluorescence detection, due to losing 7 days to Hurricane
Katrina. Still, we've been able to observe two species of fluorescent
fish - a shark and a batfish, in addition to the greeneye fish that we
found in 2004. Fluorescence has been previously observed mostly in
invertebrates. The presence of fluorescent coloration in several
deep-sea fishes prompts the question about corresponding visual
adaptations.

Due to the limited submersible operations, we put more effort into
characterizing fluorescence in the open ocean surface communities --
sargassum weed fauna and plankton ("Operation Shallow Scope").
Remarkably, we found that many crustaceans of these communities --
several species of sargassum shrimp and planktonic copepods (Fig 1) --
use fluorescence very extensively to produce colored patters.

![](media/image1.jpeg){width="5.104166666666667in"
height="3.1791666666666667in"}

**Figure 1:** Some fluorescent crustaceans of the open ocean (from the
DeepScope-2005 collection). **A**: Planktonic copepod *Pontella
securifer*. Top -- male, bottom -- female. **B**: Sargassum shrimp. Note
green fluorescent leg joints and yellow fluorescent rostrum. **C**:
Close-up of another sargassum shrimp displaying three types of
chromophore cells: fluorescent cyan, fluorescent green and
non-fluorescent brown.

Preliminary characterization of their visual sensitivities confirmed
that their eyes are tuned to the wavelengths of their fluorescence. This
fact strongly supports our hypothesis that animals would tend to adopt
fluorescent coloration instead of absorption-based color because it is
much more efficient within the oceanic light field.

**2) Eye in the Sea -- Dr. Edith A. Widder**

The Eye-in-the-Sea camera was deployed a total of four times at two
unique locations in the Gulf of Mexico. From these deployments, 1,240
1-minute videos were recorded and analyzed. Type and number of
individuals present in each 1-minute video segment were noted along with
the e-jelly mode and absence/presence of the submersible. Red
illuminators, 685 nm, were fitted with 711 nm high-pass filters,
dramatically decreasing the amount of light visible to organisms at
deployment sites. Exceptional footage included schooling behavior of
deep-sea sharks (Figure 2), sixgill shark feeding behavior, and an
attack sequence from a large undescribed deep-sea squid similar to the
species recorded during ***Operation Deep-Scope 2004***. The large squid
attacked during a bioluminescent burglar alarm display by the e-jelly in
both the 2004 and 2005 footage, indicating that this innovative lure has
fantastic potential for attracting large predators that are not
scavengers.

![](media/image2.jpeg){width="3.09375in" height="2.0625in"}Figure 2.
Rarely seen schooling behavior observed in deep-sea sharks, recorded
with the Eye in the Sea camera.

Biodiversity at the two deployment sites will be compared. Species
richness will be calculated at each site and species diversity will be
calculated using the standard Simpson Reciprocal Index. We hypothesize
that noise generated from ROV and submersible thrusters deter many
deep-sea creatures. Therefore, species richness will also be calculated
in the presence and absence of the submersible to determine the effect
of submersible activity on species present.

**3) The deep-sea light environment as it is perceived by its
inhabitants (Johnsen, Marshall, Widder)**

The preliminary analyses from this cruise suggest that the camouflage of
deep-sea benthic species is not as good at greater depths (e.g. Fig.
3,4). This is exciting because it suggests that the selective pressure
for camouflage decreases with decreasing light levels. It also raises
the question of what the colors of animals at great depths are for.

In addition to digital imaging, measurements of downwelling irradiance
were made with LoLAR II, to significantly deeper depths than have made
been made before in the Gulf of Mexico. These data will be used together
with measurements of photosensitivity to provide an realistic image of
the benthic environment looks as seen by one of its inhabitants.

![](media/image3.jpeg){width="2.5694444444444446in"
height="1.9270833333333333in"}

**4) Photosensitivity and resolution of photoreceptors of deep-sea
benthic organisms (Frank)**

During Operation Deep-Scope 2005, new techniques were used which proved
to be very successful at allowing us to obtain deep-sea benthic
crustaceans with intact photoreceptors. The JSL's DeepSea Power and
Light HMI lights were fitted with orange and red cut-off filters
(minimum cut-off wavelength 580 nm -- Fig. 5). Previous work has shown
that deep-sea species are very insensitive to wavelengths above 570 nm
(Frank and Case, 1988; Frank and Widder, 1999), so collections could be
made without blinding the animals. Two collection techniques proved to
be very successful. A new, open trap design was used (Fig. 6), which
allowed us to determine why so many of the closed-design PVC traps (sent
down open and closed after 5 hours with a magnesium link) were coming up
empty.

![](media/image5.wmf){width="2.9375in" height="2.202777777777778in"}

![](media/image6.wmf){width="1.4229166666666666in"
height="2.095138888888889in"}

Large *Chaceon* crabs, that were too big to get inside the traps and get
the bait, surrounded the traps and warded off all others (Fig 7),
including hagfish and the smaller crustaceans we were after. After this,
a decoy bait bag was used, which attracted the larger crabs and allowed
the smaller crabs to enter the traps. The traps were recovered under
orange/red light and deposited into a black BioBox (Fig 8), which was
thermally insulated and light tight when closed at depth.
![](media/image7.wmf){width="3.00625in"
height="2.2041666666666666in"}![](media/image8.jpeg){width="2.2909722222222224in"
height="2.167361111111111in"}

Using the suction sampler to pick up crabs and deposit them into the
BioBox also proved to be a very effective way to collect live animals
with intact eyes. Even though over half the cruise was lost due to
Hurricane Katrina, we managed to collect 7 crustaceans -- 1
*Gastroptychus sp* (Fig. 9), 3 *Eumunida picta* (Fig. 10), 1 *Munidopsis
tridentate*, 1 *Bathynectes longispina*, and 1 large, as yet
unidentified caridean shrimp. A surprising discovery from
electrophysiological recordings revealed that *Gastroptychus* has an
ultraviolet photoreceptor, in addition to the usual blue receptor. What
such a deep-living crab, found at 550 m at the South Florida lithoherm
site, is doing with an ultraviolet receptor remains a mystery, but
preliminary data from the caridean shrimp suggests that it too possesses
UV sensitivity, while the other three crab species, found at the same
depths, do not. ![](media/image9.jpeg){width="2.5319444444444446in"
height="1.8993055555555556in"}

![](media/image10.jpeg){width="2.5618055555555554in"
height="1.9034722222222222in"}

In addition to measurements of spectral sensitivity, photosensitivity
and temporal resolution data were also collected, and are in the process
of being analyzed. Tissue was also fixed for MSP (to verify the
electrophysiological data on visual pigments) and microscopy, to examine
optical adaptations for increased sensitivity.