Collection Of Molluscs Research Articles

Nudibranch molluscs of Sakhalin Island, Northwestern Pacific: new records and descriptions of two new species

In this paper we investigate a collection of nudibranch molluscs from Sakhalin Is. by means of integrative taxonomy, including morphological analyses, and molecular data from the cytochrome c oxidase subunit I, 16S rRNA, Histone H3 and 28S rRNA markers. Material used in this study was collected during two independent research programs: the expedition of the R/V “Akademic Oparin” (Russia) to the Sea of Okhotsk, July 2019 at depths of 38–282 m, and the survey of Cape Crillon biodiversity in August 2023, at depths of 0.5–20 m. Our integrative results revealed clear cases of the unknown diversity within some groups of the nudibranch molluscs. Among the dorid nudibranchs, the new species Adalaria boussoleana sp. nov. is described and differs in morphological and molecular characters from other species of the genus. Also, among specimens of the genus Cadlina we have detected two genetically distinct groups, one is close to C. umiushi and another group likely represents a new species for science. Their morphology is similar to the diagnosis of C. umiushi and may represent a case of true cryptic diversity. Among the cladobranch molluscs our results revealed a new species of the genus Cuthonella described herein under the name Cuthonella anastasia sp. nov. Four species are recorded for Sakhalin Is. waters for the first time: Cadlina umiushi, Onchimira cavifera, Eubranchus rupium and E. alexeii. After this paper, the total nudibranch fauna of Sakhalin Is. includes 21 species. Although we have limited numbers of nudibranch species in Sakhalin waters due to low sampling effort, a comparison of the biogeographic affinities of species from different regions is consistent with the presence of a biogeographic boundary between northeastern and southwestern Sakhalin.

Investigating the Upper Holocene palaeoenvironment and human subsistence strategy in the Khor Rori coastal area by studying mollusc remains from the Inqitat plateau (Dhofar, Sultanate of Oman)

ABSTRACTArchaeological shells have a great potential for reconstructing past environments and human–environment interactions. The Inqitat plateau (Khor Rori Archaeological Park, Oman) shows rich mollusc assemblages, present in the HAS1 settlement and in a shell midden nearby (Iron Age). By analysing the environmental requirements of the species identified in the assemblages, we reconstruct the past coastal environment and investigate its exploitation by the local population and human activities during the settlement occupation. This is the first multidisciplinary investigation of Iron Age molluscs from Dhofar. Our results indicate that the environment surrounding the site was characterised by rocky shores and shallow‐water sandy to sandy‐muddy substrates, where locals collected shells. Mangrove species were recovered in few numbers, indicating that this environment was restricted or not exploited. Furthermore, a different use of shells between circular houses within the settlement and the midden was observed; in the former, species used as ornaments are more abundant, whereas, in the latter, species used for food purposes are found, confirming the primary use of the midden as a dump. The presence of easily accessible settings for mollusc collection in the site's vicinity and the richness in food resources due to a coastal upwelling makes this region very attractive for human populations.

Marine resource exploitation and human settlement patterns during the Neolithic in SW Europe: stable oxygen isotope analyses (δ18O) on Phorcus lineatus (da Costa, 1778) from Campo de Hockey (San Fernando, Cádiz, Spain)

In recent decades, investigations in the southern Iberian Peninsula have increased our understanding of the socio-economic impact of the spread of the Neolithic in southwestern Europe, including changes in marine resources exploitation. Nevertheless, considerable uncertainty still exists around the seasonality of such subsistence systems and the putative role of marine fish and shellfish to the evolving agro-pastoral economies. Earlier studies on the European Atlantic coast (including Iberia) have shown that the stable oxygen isotope (δ18O) values from the topshell Phorcus lineatus (da Costa, 1778) can be reliably used to derive seasonal sea surface temperatures (SST) during its lifespan. This information can be used by archaeologists to estimate the seasonality of mollusc collection in the past, and to shed light into settlement and subsistence patterns. This paper presents the results of a stable isotope study on archaeological shells of P. lineatus recovered from the Neolithic settlement of Campo de Hockey (Cádiz, Spain). We analysed shells from both funerary and residential contexts and found that P. lineatus was consumed year-round, but with a stronger preference during winter. Our results therefore contribute to advance our understanding of the role of coastal environments in early farming societies of southwestern Europe.

Fauna of sone groups of invertebrates of Erebuni State Reserve (Armenia

Aim. The aim of the work is to research the fauna of invertebrates in the Erebuni State Reserve. Material and Methods. As research material served invertebrates gathered in the Erebuni State Reserve. The work was carried out at the Scientific Centre for Zoology and Hydroecology, National Academy of Sciences, Republic of Armenia in the period 2019–2023. The material was from our own collections, as well as from collections of insects and mollusks of the Institute of Zoology. The identification and collection of insects and mollusks were done using standard methods. Results. An overview of some groups of invertebrates in the Erebuni State Reserve is here provided for the first time. As a result of the research, 35 species of Diptera, 15 species of Coleoptera, 44 species of Lepidoptera,10 species of aphids and 12 species of mollusks were identified. Some species are listed in the “Red Book” of Armenia and are under the protection of the state, and there are rare species and species found in the Republic of Armenia only in the reserve. 15 species of insects identified by us develop on 4 plant species included in the “Red Book” of Armenia. Conclusion. The Erebuni State Reserve is represented by a rather diverse and valuable fauna of invertebrates studied by us, including a number of rare and protected species. Species of invertebrates associated in their development with valuable wild, economically important and protected plants have been identified in the reserve. Identification of species diversity and trophic relationships of some groups of insects that develop on rare and protected plants of the reserve is relevant for natural areas under state protection, of which the Erebuni State Reserve is one.

Nomenclatural validation of two extant Congeria species, C. jalzici and C. mulaomerovici (Bivalvia: Dreissenidae) from the caves of the Dinaric karst

Two extant cave-dwelling bivalves of the dreissenid genus Congeria were recently described by Morton et Bilandžija in Bilandžija et al. (2013) as Congeria jalzici Morton et Bilandžija and C. mulaomerovici Morton et Bilandžija. Unfortunately, the volume of the Frontiers in Zoology in which the descriptions were published was online-only and did not include a Zoobank registration number (LSID), which is required for validation of new names in electronic-only publications (ICZN, 2012). In consequence, the names C. jalzici and C. mulaomerovici should not be available according to the International Code of Zoological Nomenclature (ICZN 1999, 2012). Therefore, the present note serves to validate the names C. jalzici and C. mulaomerovici by fulfilling the ICZN conditions for nomenclatural availability. The holotypes of both species are deposited in the General Collection of Recent Molluscs, Croatian Natural History Museum, Zagreb and in The National Museum of Bosnia and Herzegovina, Sarajevo. Accordingly, the date and authorship of the new species names are those of this note and not those of Bilandžija et al. (2013).

Sampling collections and metadata of planorbidae (Mollusca: Gastropoda) in Brazil: a comprehensive analysis of the Oswaldo Cruz Institute’s Mollusk Collection from 1948 to 2023

Planorbidae comprises approximately 40 genera of freshwater gastropods, including roughly 250 species. Among the Planorbidae subfamilies, the significance of Planorbinae is due to its genus Biomphalaria, whose species are intermediate hosts of the trematode Schistosoma mansoni Sambon, 1907, which causes schistosomiasis in humans and animals. Here, we present the analysis of the dataset of Planorbidae housed in the Collection of Mollusks of the Oswaldo Cruz Institute, with a special focus on Biomphalaria species. This dataset includes 7,267 lots originating from 55 countries, representing 20 genera and 75 species collected from 1948 to 2023. Collections were performed in all regions of Brazil, comprising specimens from 26 states and the Federal District, particularly from the Southeast and Northeast. Within the dataset, Biomphalaria includes 3,926 lots of 31 species from 42 countries. These records will help improve our comprehension of schistosomiasis transmission dynamics and the geographic distributions of these medically important species.

The fish helminth fauna of Lake Sevan during a period of water level change

Aim. The aim of the work is to study the fish helminth fauna of Lake Sevan basin.Material and Methods. Fish helminths and molluscs were collected from the Lake Sevan basin. A total of 214 specimens of fish were studied. The collection, cameral processing and determination of the material was carried out according to generally accepted methods. Statistical processing of the material was carried out using the BioStat 2009 computer program. 124 specimens of molluscs were examined from the littoral of the Lake Sevan. The collection and identification of molluscs was carried out according to generally accepted methods. The work was carried out at the Scientific Centre of Zoology and Hydroecology of NAS of the Republic of Armenia. Its own collections have been used as material.Results. Trematodes, cestodes, nematodes and acanthocephals were found аs a result of studies of fish from the Lake Sevan basin. The total infestation of the fish by helminths was 27.1 %. Six species of helminths have been identified, two of which are the first to be recorded in new hosts in Armenia. The higher infestations of fish were noted by metacercariae of the trematode Diplostomum sp. and plerocercoids of the cestode Ligula intestinalis. A brief analysis of the infestation of fish by the detected helminths is given.Conclusion. The species composition of the helminth fauna of fish in the Lake Sevan basin was studied. Pathogens of dangerous helminthiases causing the death of fish have been noted. Studies of the helminth fauna of fish in the Lake Sevan basin are relevant and will be continued. Most of the species of fish affected by helminths are of economic importance. Some species of the helminths which were found are very invasive and cause great damage to the fisheries of the republic.

The Amphibulimidae pulmonate forest snails deposited in the Malacological Collection of the “Museo de Biología de la Universidad Central de Venezuela – UCV”

Introduction: Since 2014, the “AM Project” (Brazil) has been conducting taxonomic, bioecological and conservationist research on molluscs present in the Caribbean continental territory of Venezuela, with special emphasis on its land (terrestrial and arboreal) forest species (Agudo-Padrón 2021, Agudo-Padrón & Vera-Caripe 2022). Up to date, these aspects of the natural history of this geographic region have/ had been poorly studied. Objective: Substantial update of this knowledge through the unprecedented curatorial review of the collection of molluscs deposited in the malacological collection of the “Museo de Biología de la Universidad Central de Venezuela – UCV”, based in city of Caracas. Methodology: Between October 2022 and February 2023, a taxonomic review and examination of material from forest snails of the family Amphibulimidae deposited in the mollusc internal collection of the Museum was performed. Results and conclusions: Determination of fourteen (14) species, collected/ found in 16 geopolitical entities of the country, which were taxonomically grouped into one (1) family and two (2) genera.

The impact of climate changes on the ranges of invertebrates (Diptera, Molluska) in Tavush province of Armenia

Aim. The work’s aim is to study the species composition of invertebrates (Insecta, Molluska) of the Tavush province of Armenia and changes of their ranges due to climatic conditions.Material and Methods. Our own collections of 2021–2022 from different areas of the Tavush province and the collections of invertebrates of the Scientific Centre of Zoology and Hydroecology served as study material. The collection and identification of dipterous insects and mollusks was carried out according to generally accepted methods. The work was performed at the Scientific Centre of Zoology and Hydroecology The scientific material is stored in the collection fund of the Scientific Centre.Results. As a result of our studies of invertebrate species composition, 28 species of horseflies (Tabanidae) are currently listed for the Tavush region: 27 species of phytophagous gall midges (Cecidomyiidae) and 10 species of mollusks. As a result of warming climate change new changes of locality have been registered for: 6 horsefly species S. (N.) caucasicus, Ch. (H.) f. flavipes, Ch. ludens, T. unifasciatus, T. indrae vappa, T. miki; 4 phytophagous gall midge species A. verbasci, D. tortrix, S. euphorbiae, R. terminalis; For one species of mollusk, H. buchi, there are new localities. All these species have expanded their habitat: in horseflies, changes in the range along vertical zonality are observed.Conclusions. As a result of this research, it was revealed that as a consequences of climate change, the ranges of some species of invertebrates – horseflies, gall midges‐phytophages and mollusks – have expanded compared to the data of previous years. All species in which there is a direct dependence of range change on climatic conditions can be further considered as bioindicators of climate change.

Molluscs of the family Bithyniidae (Mollusca, Gastropoda) of Tyumen Region

The work is based on a study of long-term collections of molluscs of the family Bithyniidae from the waterbodies of the Tyumen region (Western Siberia), located within the world’s largest Ob-Irtysh natural focus of opisthorchiasis. Difficulties with species identifications of bithyniid snails, the first intermediate hosts of Opisthorchis , necessitate the publication of photographic images of Bithyniidae shells and an identification key based on discrete morphological characters. It has been established that 14 species of Bithyniidae belonging to five genera inhabit the Tyumen region, an annotated list of species is given, and a brief zoogeographical description is given. The most abundant species are Digyrcidum starobogatovi and Boreoelona sibirica, whereas Paraelona milachevitchi were found solitary.

Of missions and marshes: Stable isotope analysis of Mission-Era Guale oyster harvesting on St. Catherines Island, Georgia

This article presents the results of oxygen stable isotope analysis on eastern oyster (Crassostrea virginica) samples (n = 25) from a Mission-Era (ca. AD 1565–1680) site, Pueblo Santa Catalina de Guale, on St. Catherines Island, GA. Stable isotope analysis was used to assess the seasonality of oyster harvesting on St. Catherines Island during the Mission Era to better understand how Spanish colonization and the Catholic mission system may have impacted Guale foodways. Five eastern oyster left valves were sampled from each known neighborhood of Pueblo Santa Catalina de Guale. Existing data regarding the seasonality of pre-colonial mollusk collection on St. Catherines Island and elsewhere in the coastal Southeast are discussed in conversation with the results of this analysis. This work indicates that Guale residents of St. Catherines Island during the Mission Era were harvesting oysters most intensely during cooler months. This pattern is consistent with estimates of pre-colonial shellfishing seasonality across the region and may even represent a modest increase in the seasonal constriction of shellfishing when compared to data from the preceding period. Salinity estimates based on the isotope data also suggest Guale people during the Mission Era were collecting from a comparatively narrower range of estuarine habitats. We argue that these subtle shifts are a consequence of the reorganization of Guale labor associated with missionization.

Mollusc collection and Holocene palaeogeographical evolution in a southwestern iberian estuary: Statistical analysis of the early Holocene Cañada Honda shell midden (SW Spain)

The malacological analysis of the Cañada Honda shell midden (Tinto-Odiel estuary, SW Spain) has allowed an approximation of the palaeo biodiversity of this sector during the Mesolithic. During this period, the progressive marine transgression caused the flooding of this estuary, coinciding with an initial intensive capture of the bivalves Lutraria and Ruditapes decussatus in the northern and southern sector of this site, respectively. In a second phase, Ruditapes decussatus was the main collected species in all sectors. This last period coincided with some diversification in catches, still dominated by Ruditapes decussatus but with significant proportions of Cerastoderma edule. This stage witnessed a progressive sedimentary filling of the estuary and the creation of marshes and barrier islands. The almost total fragmentation of the specimens would imply that the surface of this shell midden was exposed for a long time while in use. In addition, an occasional charring of some molluscs has been detected. The main molluscs of this site are also the most abundant in other later shell middens (∼cal 5.2–4 kyr BP), indicating an important perpetuation of the collecting and/or eating habits in this environment. All the species determined in them are also currently found in this estuary and its surroundings, where they are also captured.

Biological and Chemical Monitoring of Rostov NPP as Effective Tool to Prevent Biological Disturbances in the Circulation and Technical Water Supply Systems

The technical and circulating water supply systems of nuclear power plants use water from natural or technical water bodies to provide the water supply to the nuclear power plants. Individual elements and equipment of technical water, are called technical water supply systems. In technical and circulating water supply systems, biological fouling is a collection of microorganisms, algae, molluscs, sponges, bryozoans and other biological organisms that have settled and developed on the heat exchange surfaces of units, in pipelines and on the structures of circulating water coolers. This fouling is caused by the introduction of micro-organisms and dispersal forms of fouling organisms with water from the source. In order to prevent and eliminate biological fouling on the equipment of technical and circulating water supply systems of nuclear plants, Rosenergoatom Concern JSC has adopted a production programme aimed at regular biological and chemical monitoring of water supply systems of nuclear plants.

Molluscan Diversity Present in Tawarja River at Peth in Latur District of Maharashtra

Latur district is a part of Maharashtra's Marathwada region in the southern part, which is geographically located in the Deccan plateau between 17°52′ and 18°50′ North and 76°18′ and 79°12′ east. It is typically 631 meters (2,070 feet) above mean sea level on the Balaghat plateau. Manjara is the main river which flows on the Balaghat plateau along with its tributaries: Terna, Tawarja and Gharni. The other three tributaries of Manjara are Manyad, Teru and Lendi which flow on the northern plains. Tawarja originates near Murud in Latur taluka and joins the Manjara river at Shivani on the Latur-Ausa boundary. The study was necessary for evaluating the ecological state of water bodies with the help of freshwater molluscs with studies focusing on variety, distribution, and ecology. Two sampling sites were chosen along the Tawarja River in Peth Village for mollusk collection, and these locations were carefully organized from the river's source to its confluence point following various land use/cover patterns. Throughout the course of the research, a total of 13 taxa were noted from all sample sites. The molluscan community was represented by two classes, namely Bivalvia and Gastropoda, with three species belonging to the former and ten to the latter. Three species and one family—the Unionidae—belong to the class Bivalvia. Gastropoda class had three orders, including Mesogastropoda, three families, and seven species. The study's crucial conclusions, which demonstrated that gastropods outnumbered bivalves, were taken. These species can be utilized as bioindicators of pollution and ecosystem health. The findings of this study might contribute to better molluscan fauna management and conservation in the area.

Biodiversity of certain invertebrates (Insecta, Molluska) of the Azat River gorge, Armenia and their bioecological features

Aim. The aim of the work is to study the biodiversity of certain invertebrates (Insecta, Molluska) of the Azat River gorge and their ecological and biological features.Material and Methods. Invertebrates collected in the Garni‐Goght‐ Geghard section of the Azat River gorge in the period from 2015 to 2021 served as study material.The work was carried out at the Scientific Center for Zoology and Hydroecology of the National Academy of Sciences of the Republic of Armenia. Our own collections have been used as material, as well as collections of insects and mollusks of the Institute of Zoology.Results. As a result of studies of the species composition of invertebrates of the Azat River gorge (Geghard, Goght, Garni) we found: 25 species of horseflies (Tabanidae: Diptera), 24 species of phytophagous gall midges (Cecidomyiidae: Diptera); 13 aphid species (Aphididae: Hymenoptera); 17 pyralid moth species (Crambidaе: Lepidoptera) from 5 subfamilies (Crambinae, Evergestinae, Pyraustinae, Spilomerlinae, Glaphyriinae); 19 species of mollusks (Molluska): 3 species of freshwater mollusks from 3 families (Physidae, Planorbidae, Ancylidae), 16 species of terraneous mollusks from 10 families (Succineidae, Vertiginidae, Orculidae, Pupillidae Valloniidae, Enidae, Vitrinidae, Endodontidae, Limacidae, Helicida). The bioecological features of these insects and mollusks have been studied and distribution by biotopes, revealing changes in the species composition of some groups due to anthropogenic factors.Conclusion. As a result of the researches undertaken, a wide variety of invertebrates has been frevealed. They occupy all ecological niches and are found in all plant formations of the Azat River gorge. Most of the insect species are of economic importance. Research on invertebrates of the Azat river gorge is very promising. Works in this direction will be continued with the involvement of new research groups.

António da Costa Paiva (Barão de Castelo de Paiva) (1806–1879): his malacological collection from Madeira in Universidade de Coimbra, Portugal

The Museu da Ciência da Universidade de Coimbra (MCUC) (Science Museum of the University of Coimbra) hosts an important historical collection of land and freshwater snails from the Madeira Archipelago. This collection of 1,768 specimens (120 recent taxa within 20 families) was recently catalogued and digitized. Specimens in MCUC collections were recognized as being provided by António da Costa Paiva (Barão de Castelo de Paiva). This Portuguese nobleman also donated other mollusc collections to different scientific institutions and natural history museums in Portugal and abroad in the mid nineteenth-century. The study of the origin of the MCUC mollusc collection, beyond the data associated with the specimens, is important to the research on the endangered fauna of the Madeira Archipelago. This work precedes a comprehensive study ongoing in MCUC regarding the species occurrence and the systematic review on a great number of species hosted in the museum collection.

Ecological and parasitological characteristics of the “Fasciola hepatica L.–Lymnaea (Galba) subangulata” system

Background. Fasciolosis is one of the most common zoonoses in the world, caused by the trematode Fasciola hepatica L. This helminthiasis leads to significant economic damage in animal husbandry and can pose a direct threat to human health. Today, in the context of climate change, detailed knowledge of the biological characte­ristics of the trematode F. hepatica circulation will make it possible to predict outbreaks of fasciolosis on farms in detail and plan effective measures to combat this dangerous disease. The purpose of this work is to clarify some aspects of F. hepatica biology within Berdychiv district belonging to the forest-steppe zone of Zhytomyr region. Material and Methods. The work was carried out during 2020–2021. Collections of mollusks from water bodieson the territory of Berdichevsky district of Zhytomyr region served as the material for the research. Their identification was carried out by conchological features. Conventional methods were used for the parasitological study of mollusks. In total, more than 2000 mollusks Lymnaea (Galba) spp. were examined. Sampling of water and mollusks was carried out from four pasture reservoirs. Results. The main intermediate host of F. hepatica is the mollusk L. (G.) subangulata in the territory of Berdychiv region; L. (G.) truncatulaplays a secondary role in the distribution of this trematode. It was noted that the carriers of F. hepatica partenites are mainly mollusks with a shell height of 4.0 to 8.2 mm. New data on the dynamics of infection of L. (G.) subangulata with the trematode F. hepatica was obtained. The dynamics of infestation of these mollusks with F. hepatica cercariae shows a stable uniform character in the form of a two-peak curve, with peaks in May (2.51 ± 0.88 %) and August (9.19 ± 1.78 %). The overall prevalence of L. (G.) subangulata invasion by fasciola cercariae in the studied water bodies in 2020 was significantly lower than in 2021. Conclusions. In modern climatic conditions, in the territory of the region, permanent water bodies have become fasciolosis foci and common places for the settlement of L. (G.) subangulata, infected with F. hepatica cercariae. The most favorable environmental conditions for fasciola and its intermediate hosts develop in spring; accordingly; for the definitive hosts, this period is quite dangerous in terms of infection of animals.

Sustainable Indigenous Fishing in the Pre-Contact Caribbean: Evidence and Critical Considerations from Carriacou, Grenada

Multiple studies reveal pre-1492 anthropogenic impacts on Caribbean fisheries that are consistent with overfishing, including changes in targeted prey, shifts in marine habitats exploited, and decreases in the average body size of taxa. At the Indigenous Caribbean village of Sabazan (AD 400–1400) on Carriacou, Lesser Antilles, post-AD 800 declines in fishing, increased mollusk collection, and changes in resource patch emphasis accord with the archaeological correlates of resource depression predicted by foraging theory models from behavioral ecology. Here, I apply foraging theory logic and abundance indices incorporating body size and fish habitat to test the predictions of expanded diet breadth, declining prey body size, and shifts to more distant fishing patches that are typically associated with overfishing. Results uphold a significant decrease in overall fishing, which may be due to habitat change associated with the Medieval Warm Period. Indices of fish size and resource patch use do not meet foraging theory expectations for resource depression, however. Instead, they suggest an absence of resource depression in the Sabazan fishery and at least 600 years of sustainable fishing. I review similar findings for other Caribbean archaeological sites with either negative evidence for fisheries’ declines or quantitatively demonstrated sustainable fishing. These sites collectively serve as a critical reminder of the heterogeneous trajectories of Indigenous social–ecological systems in the pre-contact Caribbean and the need for meta-level analyses of the region’s ancient fisheries. I discuss the application of the sustainability concept in archaeological studies of fishing and conclude that a more critical, explicit approach to defining and measuring sustainability in ancient fisheries is needed.

Middle and Late Pleistocene terrestrial snails from the Middle Dniester area, Ukraine (based on Mykola Kunytsia’s collections)

Extensive collections of land molluscs from the many sections of Middle and Late Pleistocene deposits in the region of the Middle Dniester River were made by Professor Mykola Kunytsia (1925–2002). These collections, now at the Natural Museum, Yuriy Fedkovych Chernivtsi National University, were for the most part analysed, but remained partially unpublished. M. Kunytsia used them for regional reconstructions of palaeolandscapes during various stages of the Pleistocene. In our study, we used these collections to assess the land snail diversity in the region during consecutive stages of the Middle and Late Pleistocene. Our analysis of faunas of cold and warm stages showed that the latter were more diverse. While all or most of the cold stages had many species in common, the faunas of the warm stages were more heterogeneous. Such a feature may play an essential role in Quaternary biostratigraphy.

A cross-sectional study on dermatoses among underwater workers: a new clinical sign of peculiar distribution pattern of lesions in sea urchin prick reaction revealed.

The pattern of dermatoses among underwater workers is undocumented and, hence, worth studying. The objective of the study was to document the pattern of dermatoses among underwater workers in a tropical seaside area. A population-based cross-sectional study of 1year from April 2015 among people regularly involved in underwater occupation, especially the collection of mollusks. Among 62 participants analyzed, the commonly noted dermatoses were scars of previous injuries, sea urchin prick reaction, onychomycosis, tinea versicolor, dermatophytosis, warts, and intertrigo. These workers stabilize their position under water by fixing elbows and knees to rocks, where they get accidentally pricked by sea urchins attached to the rocks. Hands also get pricked by sea urchins while trying to pluck mollusks from rocks, thus leading to the predominance of lesions in elbows, knees, and hands. Documenting the pattern of dermatological diseases in any group of underwater workers has not been done previously. Along with doing that, the study also brought to light the existence of a rare disease, sea urchin prick reaction, in notable proportions among an underprivileged group. This study also detected a previously unrecorded clinical finding of a peculiar distribution pattern of lesions over the body in patients with sea urchin prick reaction. The evidence toward possible commensalism between the two species of organisms noted in this study extends its scope beyond the realms of dermatology and opens new areas for research in other branches of science also.