The term 'Lazarus Species' is given to a species of plant or animal that had been presumed to have gone extinct, but has been rediscovered subsequently, said Environmentalist and activist Dr Jagath Gunawardana.
This particular term denotes within it the thought to have gone extinct for some time and being found again yet needing to be protected in order to not become extinct once again.
He also noted that it is especially important to have the opportunity to socialise a number of facts due to the great excitement that has arisen in recent times about the rare Crudia zeylanica plant.
According to the biblical character Lazarus who was brought back to life by Jesus four days after death, species that are rediscovered after a lapse of time are known as ‘Lazarus Species’. “Although I have never heard or seen this term used in this country, there are a number of specialities that deserve to be introduced,” Dr Gunawardana elaborated.
The Crudia zeylanica plant, which is thought to have been extinct for more than three decades, can be re-introduced as another Lazarus species.
Even from Sri Lanka, a number of such Lazarus species have been reported through rediscovery over the past few decades.
“The reappearance of an endangered species of plant or animal anywhere in the world, or the addition of another species of Lazarus, is particularly good news. The transformation of any species from Sri Lanka into a species of Lazarus is extremely valuable, important, and especially exciting,” Dr Gunawardana added, paying tribute to all Sri Lankan researchers, both named and unnamed, who made such discoveries.
Horawel (Stemonoporus moonii)
Stemonoporus moonii or Horawel is a species of an endemic genus, only recorded in Walauwatta-Waturana freshwater swamp forest in Bulathsinghala. Stemonoporus moonii was discovered in 1979 by a group of scientists including Prof. Nimal Gunatilleke and Prof. Costermans at the Walawwatta Estate in Bulathsinghala.
Horawel is a rare and endemic plant currently located in a 12-acre private swamp in Sri Lanka.
It is said that a former director of the Peradeniya Botanic Gardens, Alexander Moon, identified the forest around 1820. Prof. Gunathileka said that this endemic plant was first identified in 1820 by the then Superintendent of the Peradeniya Botanic Gardens, Alexander Moon, and this plant had not been seen in Sri Lanka for about 160 years. So the researchers believed that the plant was extinct. However, Prof. Costermans and Prof. Gunatilleke were able to rediscover this plant in 1979.
“Although it belongs to the genus Dipterocarpaceae, it does grow up to 8-10 m tall. Horawel has been included in the IUCN Red List as a critically endangered plant and if it becomes extinct there will be no Stemonoporus moonii anymore,” he noted.
Reportedly, one of those special features of this plant is its flowering stems. The leaf temple of these plants is similar in shape to the leaves. The foliage is about 45 cm long and 8 cm wide. The soft leaves are light red and extend down the stem. A straight trunk can be seen on the evergreen vines that usually do not have branching. The flowers of these plants are small white. The fruit is a spherical fruit about 3cm in diameter. Due to its slow growth, only a small number of these plants can be seen today. This small shrub is found in the understory of swamp forests and in marshy, periodically inundated areas near slow-running streamlets.
Most swamp forests have been converted to rice fields.
“Prof. Costermans who was a Guest Professor at the University of Peradeniya told me that a plant called Horawel was found in the Kalutara area and now that the plant was nowhere in the world. He suggested doing a study on it again. There is a swamp area near Walawwatta,” he noted. With the help and permission of the family of the owner of the Walawwatta, Dr. Mahinda Wijesekera, Prof. Gunatilleke and Prof. Costermans entered the Wathurana swamp forest and engaged in studies and research. Then finally the team was able to rediscover the plant a few days later.
Suwanda (Mesua stylosa)
The other plant that was rediscovered and can be known as a Lazarus Species is Mesua Stylosa. This is a species of Na genus with slender oblong leaves that grows to a height of 10 - 15 m. Today only a small number of these plants remain. The remaining plants are small in size. In the past, the forest was rich in fragrant trees. A survey of about 1988 found evidence of large-scale deforestation. The flowers here are white fragrant flowers similar to Na (known as the brother of our National tree).
Prof. Gunatilleke elaborating on the threats facing this particular wetland states, “This forest is so protected because it is part of private land. The Wijesekera family has made a great contribution to protecting this forest. However, illegal sand mining, poaching and logging have become a major threat to the forest. IUCN Red List cited this ironwood tree is threatened because its habitat is being converted for rice cultivation.”
Adenomus kandianus
This species is endemic to Sri Lanka and for a long time was known only from the general type locality of Ceylon (Sri Lanka). The scientific name appeared to suggest that it might have been collected in the vicinity of the city of Kandy in central Sri Lanka. However, all of the Central Province was referred to as Kandy in the late 19th century, when the species was described. Mendis Wickramasinghe’s research reports showed that in 2009 the species was rediscovered in the Peak Wilderness Sanctuary in the Central Province. Its eastern boundary is adjacent to Horton Plains National Park.
There had been no sightings since the original description and the species was believed to be extinct. According to the IUCN Red List the habitats of the Adenomus kandianus both adults and juveniles of the species have been recorded living in and around clear, relatively cold, fast-flowing streams in montane cloud forest that are shaded with 70–90 per cent tree canopy cover. Water temperature in the streams range between 16.9–18.6 degrees C (17.8 ± 0.5 degrees C) and the depth of water varies from 40–80 cm. Individuals have been commonly observed on the moss-covered boulders by, next to, and in streams.
Pseudophilautus stellatus
Pseudophilautus stellatus (Kelaart 1853) was again rediscovered by Wickramasinghe from the Peak Wilderness, Central Hills of Sri Lanka. The species, till now known only from its lost holotype, was the first shrub frog described from Sri Lanka and had not been reported since then. It was thought to have become extinct for nearly 157 years, being the amphibian species ‘lost’ for the longest amount of time.
The team including Wickramasinghe has conducted a molecular phylogenetic analysis, on which basis the species is well-differentiated from all other Pseudophilautus sequenced so far. A systematic survey was carried out over a two-year period, in order to document the amphibian diversity across an elevation gradient (550 m to 2240 m), in the Sripada massif, Peak Wilderness (part of the Central Hills World Heritage Site) of the Central province, of Sri Lanka. Surveys focussed on terrain where not much light has been shed by scientists, due to difficulty in accessing these sites owing to harsh weather conditions and tough trails. Three frogs were collected and were stored in 70 per cent ethanol, and tissue samples for molecular work were taken from these specimens. Sex and maturity were determined by examining secondary sexual characters, or when absent, by examining the gonads through a small lateral incision in the specimen.
Pseudophilautus hypomelas
This species is endemic to Sri Lanka and was previously known only from the imprecise type locality of Sri Lanka, rendering it impossible to map. It has since been rediscovered by Wickramasinghe from Peak Wilderness Sanctuary, Loolkandura, Colony in Vidulipura village in Norton Bridge, and Maussakele.
This species is uncommon and its abundance varies seasonally. A decreasing population trend is inferred from the ongoing decline in the quality and extent of this species’ habitat. Wickramasinghe showed that within the Peak Wilderness Nature Reserve, Sripada Peak is a place of worship of all religions in the country of Sri Lanka, with millions of visitors, especially during the six-month-long peak tourism season. During this time, a large amount of garbage collects, light pollution increases, and the forest is exploited.
Pondicherry Shark (Carcharhinus hemiodon)
Previously assessed as Vulnerable, this species has been reassessed based on improved information.
Pointing out that the last record was in 1970 and it has not been seen anywhere since, Madhura de Silva said so after a careful examining of the images and scrutinising the relevant discussions with Rex Ian De Silva who is a pioneer Sri Lankan Diver, Underwater and Astro Photographer and Martial Arts Sensei and Writer.
This is the first record of a shark in freshwater from Sri Lanka. “The Juvenile Bull Shark, which has been recorded from Sri Lanka, thrives in freshwater in parts of its range. The Juvenile resembles the Pondicherry Shark in general appearance, but the Juvenile Bull Shark differs from that species as they have small eyes,” he noted.
The recent updates of the IUCN Red List show that the rare shark occurs (or occurred) in inshore localities and habitats subject to large, expanding, and unregulated artisanal and commercial fisheries. If still extant, it is probably caught and utilised as a by-catch of other fisheries, although market surveys have failed to locate it. Its populations are thought to have been severely depleted as a result of this exploitation.
Crudia zeylanica
Research Assistant in Plant Taxonomy and Conservation Research project at the National Institute of Fundamental Studies (NIFS), Himesh Jayasinghe, was the first to discover Crudia zeylanica after it was believed to be extinct.
Speaking to Ceylon Today, he said a conditional approval was given for the Road Development Authority (RDA) for construction work by the Central Environmental Authority (CEA) and following that, this plant was found while conducting the Environmental Impact Assessment (EIA) test for the RDA project at the end of 2018.
After that, with the help of the RDA and the CEA, they conducted a survey to find out more about the plant and then it was discovered that it is not the only surviving tree, as it was found in six different locations in Sri Lanka, including in the areas surrounding the Kelani Ganga.
The Sri Lanka Legume or Crudia Zeylanica was discovered and named as a new species in 1868 and was eventually presumed to be extinct. Thus the IUCN Red List of 2006 categorises it as extinct.
It was also added to the National Red List of 2012 prepared by the Ministry of Environment. It was known only from the herbarium specimens collected more than a century ago, and drawings, since there were no photographs of a living plant until this rediscovery in 2019 by three young scientists. Crudia zeylanica had undergone a full cycle of being identified as endangered, extinct, and rediscovered and now facing extinction once again.
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