Flag #147 Expedition

Transcription

1 Flag #147 Expedition The Continuation of A Photographic Survey of the Living Mollusks In The Coastal Honduran Region Including The Utila Cays with Emphasis On Two Subspecies of Volutes and Murex Rawlings, June 2012 Charles E. Rawlings, M.D., J.D. FN Old Salem Road Winston-Salem, NC rawlings@rawlingslawfirm.com

2 Although the Bay Islands of Honduras including Roatan are well known for diving and tourism, the Northern Coastal region of Honduras as well as the small Cays around Utila are practically unexplored from a diving standpoint. Moreover, the conchological life in those areas is even more poorly documented and has only been sporadically sampled to date. Over the past several decades multiple new species have been identified from this region while others have had their range extended into this area. Over the course of the years, several very similar species or subspecies have been identified with questions arising as to their relationship. The prime examples are the pair Voluta polypleura hennequini from Trujillo Bay and Voluta polypleura sunderlandi from the Utila Cayes and the pair Vokesimurex donmoorei from Trujillo Bay and Vokesimurex cabritti from the Utila Cayes. Up until our Flag #147 Expedition to Trujillo Bay neither the volute nor murex had been photographed alive in its natural habitat. (See Report of Flag #147 Expeditions by Rawlings 2011). This year I returned again carrying Flag #147 with the goal of photographing both these pairs of enigmatic species live in situ so as to further delineate their relationship. These objectives were achieved, and the expedition was a complete success. Moreover, several other species, heretofore never photographed alive in their natural habitats, were found and photographed. These included Latirus abbotti of which only 5 or so specimens have been discovered and the newly described Cancellaria reticularis. Following my arrival in Roatan, we secured provisions and alcohol for specimen preservation and proceeded to board the shrimp boat. Unlike last year the seas were calm and the crossing to Trujillo Bay took only about 5 hours. We arrived in the Bay early and began preparations for a long night of diving. We stayed in Trujillo Bay for 3 nights and 4 days with our time apportioned much like the last expedition. Over the course of the 3 nights, I dove in 5 different locations for a total of 8 dives. As previously, the majority of dives were undertaken at night so as to record and collect the conchological material for photography the next morning. The majority of photographs were taken at sunrise so that the animal was active but enough light was present for photography. Unlike last year, the seas were flat, the wind was mild and the water was much clearer. Again all diving and photography was conducted between 85 and 86 West longitude in Trujillo Bay. Depths of the dives ranged between 35 and 65 feet. During my time there I was able to photograph the species I encountered the last trip including Voluta polypleura hennequini and Vokesimurex donmoorei. In addition I was also able to obtain first photographs of the newly described Cancellaria reticularis and the spinous murex Chicoreus mergus feeding on a scallop. Finally, I collected a living hennequini with the hopes of keeping it alive until we arrived in the Utila Cays and

3 locate a specimen of the subspecies Voluta polypleura sunderlandi, at which time I could photograph them together, side by side, to compare the living animals. Trujillo Bay appeared unchanged from our last expedition except for a slight increase in water clarity. For a complete description, please refer to my Flag #147 Report from last year. With regard to the conchological specimens, again the species found were similar to those from last expedition. The additions included the murex, Chicoreus mergus, Cancellaria reticularis and the very rare moonsnail, Naticarius tedbayeri. The moonsnail specimen found was one of the largest on record and the animal was a beautiful red flecked with blue. Thus, the Trujillo Bay portion of the expedition was a success with multiple photographs obtained and a living hennequini volute in an aquarium ready to be photographed side by side with a sunderlandi. We next headed to the Utila Cays. The Utila Cays proper are a group of small islands or Cays to the south and west of the Honduran island of Utila. Our destination was the triangle of ocean between Sandy Cay, Southwest Cay and Ragged Cay. It is within this triangle that the majority of unique conchological specimens are to be found. The steam over from Trujillo Bay took about 5 hours in the middle of an immense thunderstorm and 9 to 10 foot seas. The lightning display was a sight to behold. Once we arrived at the Cays we anchored just to the west of Sandy Cay to begin our search. We were to explore the Utila Cays for the next 5 days and 5 nights. These three Cays, Sandy, Southwest and Ragged Cay are mere spits of sand with a collection of palm and pine trees atop them. All have one building on them ranging from the abandoned one room shack on Ragged Cay to a several room house on Sandy Cay. None were an acre in size and Ragged Cay could be measured in square yards. The bottom substrate and topography were completely different from Trujillo Bay. The substrate ranged from coarse white coral rubble to fine white coral rubble to soft fine coralline sand. There were healthy patch reefs found frequently in the area and depths ranged from 100 feet to wading depths. The topography was gradually sloping from the open ocean to the base of the Cays where, at about 50 feet, an abrupt slope ended in about 10 to 15 feet of water. The bottom was covered in a combination of dense turtle grass, eel grass and Halameda algae if no reef structure were present. No mud, silt or dark volcanic sand could be found; the entire bottom was pure white coralline debris with water visibility of 50 to 100 feet. One of the most unique aspects of this area was the presence of white holes or areas of coralline sand or rubble surrounded by fields of turtle grass. These holes averaged 12 to 20 feet in depth and were plainly visible from the boat. We collected the majority of our conchological specimens from these areas.

4 Over the course of the next 5 days and 5 nights I totaled 14 dives most averaging longer than an hour due to the shallow depth. We alternated between the three Cays in terms of location plus the white holes in between. Diving was conducted as in Trujillo Bay with night for collecting and morning for photography. Multiple conchological specimens were collected and photographed including the very rare Latirus abbotti, Strombus gallus, an unusual Bonnet species and several cone species including the Cay s form of Conus harlandi, Conus daucus and Conus regius. More importantly, I was able to collect and then photograph side by side Voluta polypleura hennequini with Voluta polypleura sunderlandi plus the murex Vokesimurex cabritti, thus comparing it with Vokesimurex donmoorei from Trujillo Bay. All dives were between 10 and 90 feet in depth and between 16 and 17 North Latitude and 86 and 87 West longitude. As mentioned previously I was able to collect both forms of Voluta polypleura in this area hennequini and sunderlandi and photograph them together in their natural habitat. It appears upon close inspection of the animals that they are one and the same and thus these volutes are not subspecies but merely color forms of the same shell. Hennequini s shell is darker due to the higher mineral content and darker substrate upon which it lives in Trujillo Bay. Sunderlandi is a white to cream color due to the substrate upon which it lives the bright white coralline sand of the Utila Cays. DNA testing would confirm the results of these photographs. The murex Vokesimurex donmoorei and Vokesimurex cabritti were also collected and photographed in their native habitat. These animals do appear to be either separate species or subspecies based on their photographs and shell morphologies. Vokesimurex donmoorei is clearly darker but the animal itself differs from that of Vokesimurex cabritti as well especially in the foot appearance and eye stalk appearance. Again, DNA analysis would confirm this hypothesis. In conclusion, my expedition to Trujillo Bay and the Utila Cays carrying Flag #147 was an unqualified success. Over the course of the 8 days I did 22 dives amassing over 30 hours of time underwater. I identified over 30 species of mollusks from these two regions including Chicoreus mergus, Latirus abbotti, Cancellaria reticularis, Strombus gallus, Conus daucus, and Conus regius. Moreover, I was able to photograph the subspecies of Voluta polypleura from that region side by side and conclude that they were merely color forms. I was able to photograph both species of spiny murex Vokesimurex cabritti and Vokesimurex donmoorei and concluded that they did constitute separate species. Finally, first photographs of multiple species were obtained in their native habitat including the volutes, the

5 muricids, Latirus, and Cancellaria. As an aside, we also spotted a significant number of the lionfish Pterois volitans, a non-native nuisance, in the Utila Cays. Flag #147 Expedition to Honduras was a success.

6 Captions

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8 1. Map of Utila Cays showing Sandy Cay, Southwest Cay and Ragged Cay. All dives in the Cays were performed in the triangle delineated by these islets.

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10 2. Flag #147 on Expedition in the Utila Cayes

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12 3. Ragged Cay

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14 4. Latirus abbotti Note the bright red animal an adaptation to deeper water. This specimen was in 95 feet of water in Utila Cays. My deepest dive.

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16 5. Chicoreus mergus Feeding on a small scallop. Note the soft bottom. This substrate promotes frond growth. This photo was taken in 45 feet of water in Trujillo Bay.

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18 6. Naticarius tedbayeri A very rare moon snail particularly at this size. This photo was taken in 40 feet of water in Trujillo Bay.

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20 7. Voluta polypleura sunderlandi First photographs of this rare volute found in the Utila Cayes. This photo was taken in 30 feet of water just off Sandy Cay.

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22 8. Voluta polypleura sunderlandi with Voluta polypleura hennequini This comparison photograph was the primary objective of the expedition. The dark form hennequini is found in the muddy volcanic substrate of Trujillo Bay while the lighter almost white form sunderlandi is from the coralline sands of the Utila Cays. Compare the animals they appear to be the same. This photo was taken in 35 feet of water.

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24 9. Vokesimurex donmoorei This spiny murex is from Trujillo Bay. Compare it to Vokesimurex cabritti. The animals are clearly different. This photo was taken in 45 feet of water in Trujillo Bay.

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26 10. Vokesimurex cabritti This spiny murex is from deeper water in the Utila Cays. As can be seen the animal differs from Vokesimurex donmoorei. This photo was taken in 55 feet of water in the Utila Cays.

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28 11. Cancellaria reticularis First photographs of a living reticularis in its natural habitats in Trujillo Bay. This shell was only recently described, and this photo was taken in 35 feet of water in Trujillo Bay.

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30 12. The lionfish Pterois volitans A non-native species that has become a rampant nuisance throughout the Caribbean. We spotted significant numbers of these predators in the Utila Cays.