Collecting The Bermudian Endemic Killifish
For some time now, we have been discussing collecting the Bermudian endemic killifish, Fundulus bermudae. The killies are all located in the protected nature reserves which meant that permission had to be sought from the Department of Parks before any collecting could take place. I sent off a letter seeking permission and then set about learning what I could about the fish. A visit to the library at the Bermuda Aquarium, Museum and Zoo (BAMZ) revealed that Bermuda’s Fundulus have been the subject of a number of scientific studies in the past, and that they are part of a current project.
Fundulus bermudae has been around for quite some time and was first described in 1874 by Gunther. The “Field Book of Shore Fishes of Bermuda” by William Beebe and John Tee-Van, published in 1933, states that the fish was abundant in the brackish pools and ponds of the time. Papers have been written about the species in 1952, 1957, 1967 and 1980. In 1988, Able and Felley proposed that there is a second species - Fundulus relictus. They report that relictus is only known from the type locality - Lover’s Lake, a 1.2 acre pond at Ferry Reach. The major differences between relictus and bermudae involve lower fin-ray and gill-raker counts. To the casual observer, they appear identical.
A 1986 newsletter of the Bermuda Audubon Society reported that Fundulus bermudae was to be found at Bartram’s Pond, Mullet Bay. Dr. David Wingate, Government Conservation Officer, reveals that Bartrams Pond was stocked following a trans-location of specimens from Lovers Lake. The original pond was used as a dump or land-fill around the time of the second world war. The Audubon Society has since acquired the land and re-constructed a pond.
In 1993, the Department of Agriculture and Fisheries Report listed F. bermudae as being present in Trott’s Pond and Mangrove Lake. The Lover’s Lake population was listed as F. relictus, as per the finding of Able and Felley some years previous. The report went on to say that new populations had been found at Evans Pond and the small ponds of West Walsingham, on the Wilkinson Trust land. It was suggested that these populations were endemic.
In 1994, the Bermuda Audubon Society newsletter reported that Fundulus had been located in Warwick Pond.
An ongoing project involving Bruce Collette and others at Tulane University is likely to determine whether we do, in fact, have two or more species of Fundulus in Bermuda. Collette and his team will be conducting morphological and molecular systematics using material collected over the years by Collette (Sterrer).
Bruce Collette lists four distinct populations of Fundulus: Lover’s Lake, Mangrove Lake, Walsingham Pond and Evans Pond. The status of the Evans Pond population was unclear, as he had only seen one specimen and had not collected from that location (Sterrer).
I tried to obtain slides of F. bermudae but discovered that there were none available at BAMZ. Dr. Wolfgang Sterrer was very helpful and contacted Bruce Collette. He had slides in Washington, DC, and agreed to send some. Dr. Sterrer pointed out that the line drawing of F. bermudae in his book was actually wrong (the only error in the book - just my luck). The only picture that I could find was in Beebe and Tee-Van’s book .
Dr. Wingate has been surveying Bermuda’s ponds for the last 10 years. He was able to give a detailed account of the existing populations. Original populations exist in Lovers Lake, Mangrove Lake, Trott’s Pond, Walsingham West Pond, Warwick Pond and Evans Pond. Additionally, specimens have been trans-located from some of these ponds in order to establish additional populations. The Lovers Lake specimens went to nearby Bartram’s Pond and specimens from Walsingham West went to Blue Hole Park. Artificial ponds, one salt and one fresh, were created on Nonsuch Island. The saltwater pond was stocked from Trott’s Pond and the freshwater pond was stocked from Mangrove Lake. The move to freshwater necessitated a two-week period of acclimatisation but the population adapted well and is thriving.
Most of Bermuda’s ponds are brackish, if not pure seawater. Warwick Pond, however, is close to being freshwater. Dr. Wingate therefore believes that the Warwick Pond population is likely to be the most distinct, if the various populations are found to be different species.
In the afternoon of Friday, 28th August, 1998, I met with Dr. Wingate to discuss this issue. He granted us permission to collect Fundulus but suggested that we only collect from Bartram’s Pond. There are a number of concerns. As research is still ongoing to determine whether or not each pond holds a distinct species, it is imperative that specimens from one location are not transferred to another. If all captive specimens come from the same pond, control should prove easier. Secondly, Bartram’s Pond is not one of the original populations having been stocked itself from Lover’s Lake. It was therefore deemed to be a better option for collecting for the aquarium hobby.
Dr. Wingate asked for the assistance of members of our society to stock the recently created pond at Paget Marsh. Extensive restoration work has recently taken place in Paget and a new freshwater pond has been created. Dr. Wingate wishes to stock the pond with Fundulus and the nearest population is at Warwick Pond. Warwick Pond is rapidly silting up so it makes sense to trans-locate some of its population to safeguard it against possible extinction. Of course, I informed Dr. Wingate that we would be happy to assist in any way that we could. The problem, for many of our members, was that he wanted to attempt the trans-location at 4am that Sunday (30th August). I made some telephone calls but a combination of short notice and the proposed collecting time meant that only Nyon Steede and myself were available. At 4am that Sunday morning, Nyon and I joined Dr. Wingate at the Warwick Pond. Dr. Wingate had suggested that 4am would be an ideal time to catch the Fundulus. He explained that the oxygen levels in the pond would be depleted due to there being no photosynthesis of plants during darkness. This, he suggested, would cause the Fundulus to rise to the surface for air. We would then “spotlight” them with a flashlight and easily net them. That was the theory. We tried a number of spots around the pond and merrily “spotlighted” away. I even waded into the muddy, and smelly, back side of the pond. We were swarmed by Gambusia holbrooki but didn’t spot a single Fundulus. We were up early and there was no sense in calling it a day so soon. Neither Nyon or I had ever seen Fundulus in the wild so Dr. Wingate suggested that we take a drive to Bartram’s Pond.
We made stops at a pond on Belmont Golf Course and Blue Hole Park. Dr. Wingate had seen Fundulus teeming in Blue Hole during the day-time but then, in the dark of night with a flashlight, we only caught fleeting glimpses of a couple. When we caught a Fundulus in our light, it made for cover. So much for being attracted to the light. We had learned the hard way that Fundulus are unlikely to be caught in this manner.
We made our way to Bartram’s Pond. The idea had been to use the Warwick Pond as a test for our collecting methods. We would then plan an outing for the members to collect at Bartram’s. Circumstances change, and here we were, up early with collecting equipment at the suggested collecting site. By the time we reached the edge of the pond daylight was beginning to creep in. As with the other locations, “spotlighting” failed to attract Fundulus. As it got lighter, we began to see a number of Fundulus, swimming amongst the Gambusia. There were small numbers of them, just one or two at a time. They were also just out of reach of my collecting net. Believing that we would not collect any that day, we began to discuss returning on another day with a seine net. Almost ready to pack up and leave, I agreed to get into the pond in an effort to reach the few Fundulus that were swimming out of reach.
I stepped down into the pond and was about knee deep in water. The bottom of the pond was quite firm and nowhere near the quagmire of Warwick Pond. There was some detritus on the bottom that was stirred up by my standing in it. There I stood, with my dip-net submerged in front of me. I waited for a Fundulus to swim over the net and then quickly lifted it. I caught some and others swam quickly away. After catching a couple of loner Fundulus, I glanced down near to my feet. To my surprise, I was surrounded by Fundulus. They were obviously attracted by the stirred up debris from the bottom of the pond and were swimming through it, looking for food. Collecting then became easy, like shooting the proverbial fish in a barrel. In no time I had nine Fundulus in the bucket. We checked for males and discovered that there were at least two. We didn’t want to collect more. This collection was not planned and we were unsure whether our members would have tanks ready for new fish. It was now 7.30 am. Our 4am foray had lasted 3 ½ hours.
When I got the bucket of Fundulus home, I checked the sexes and found that I had 3 males and 6 females - three trios. I soon contacted our two most active fish breeders, Jeremy Lodge and Chris Roy, who were keen and ready to take a trio each. I took a trio myself. The water from Bartram’s Pond was tested and the specific gravity / salinity was found to be the same as seawater.
I took a number of slide photographs of the Fundulus that day, both male and female. Copies have been supplied to BAMZ and I have the others.
Fundulus bermudae is closely related to Fundulus heteroclitus, which can be found along the eastern coast of the United States. Dr. Wingate has found a dead female bermudae on Nonsuch Island that was at least 5 inches long. Heteroclitus have been listed as reaching 7 inches in length. We can be certain that, as far as killifish are concerned, F. bermudae is on the large side. The specimens that I collected were about 2 inches in length, the larger specimens being the females. They are a pleasant olive green in colour with a pattern of vertical bars. The male has a black spot, surrounded by a white edge, at the rear of his dorsal.
I went down to the ocean and obtained some fresh seawater that I placed in a 5 gallon tank. The tank is equipped with a sponge filter. I added two floating mops and one sinking mop to the tank and then added the trio of Fundulus. The following day I offered regular flake food that was immediately gobbled up. It is apparent that these Fundulus are very easy to maintain in captivity. They spawned in the first week of captivity, preferring the floating mops, very close to the surface of the water. I picked 8 eggs from the mops and placed them in a jar.
About two weeks later I again located eggs in the floating mops and was able to pick 9. I considered the possibility that the parents were gobbling up eggs after they had been laid so I decided to check the mops early in the morning. For the next two days I was able to pick 8-9 eggs a day, all of them being found in the floating mops, close to the surface of the water. These initial observations suggest that the fish deposit small numbers of eggs over a period of days. Regular examination of the mops is therefore necessary to gather the most eggs. The eggs have not yet hatched but hatching is expected to occur after about 3 weeks, judging on reports concerning heteroclitus.
With three trios of wild fish in captivity, I expect that we will be able to adequately supply any demand for the fish with F1 fry (first generation from wild parents). I will make the fish available free of charge. This will avoid the need to collect any further wild fish. There is already interest from the United States and the US hobbyists may be supplied with eggs, which are easier to mail that live fish.
Those members who still wish to try collecting wild Fundulus will still get their chance. Dr. Wingate still needs to trans-locate some of the Warwick Pond population to Paget Pond. Hopefully, we will be able to accomplish this in daylight hours, in the near future. It will not be as simple as collecting in Bartram’s Pond. I have since returned to Warwick Pond and baited an area with fish food. I did not see any Fundulus but I am hopeful that the fish still exists in Warwick Pond.
It is very important that Bermuda’s hobbyists take every step to protect our natural resources. Even offspring from our captive Fundulus should not be released into our ponds - unless specifically directed by Dr. Wingate. Once in our tanks, the fish might be exposed to diseases that do not exist in the ponds. Releasing fish back into the wild might also release diseases or bacteria that could harm the environment. Dr. Wingate and the Parks Department have shown trust in us and we must ensure that we prove worthy of it.
