Costa Rica ? Pura vida y caracoles !

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Costa Rica is a Central American state, in between Nicaragua and Panama. San José is its capital city ; the country has two coastlines, one on the Pacific Ocean, the other on the Caribbean Sea. Its wildlife diversity is maintained by protected natural zones created by the government. All these facts encouraged me in discovering this beautiful Hispanic country, well known for the welcome of its inhabitants, the Ticos. In September 2005 I left Paris for San José, via Caracas, for a one-month trip : not quite enough to catch a glimpse of the "Rich Coast". Travellers can find there a large choice of lodgings for every budget. Mine being of "shoestring" level, I bivouacked when possible and otherwise stayed in guesthouses. I always was most welcome, despite my being a non-hispanic-speaker lone traveller. 

My trip had three goals : to surf terrific waves, to sink myself in the tropical forest and of course to collect shells. All my wishes were fulfilled ; here follows a glimpse of my gatherings in the three most interesting sites shell-wise. 

The Pacific coast : around Tamarindo

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Near Tamarindo the monotony of long sandy beaches is broken by rocky basaltic plateaus. The tide amplitude is quite important and the intertidal zone is a rough habitat due to the Pacific waves.

On my arrival I walked along the beach searching through the high water mark, followed by a herd of abandoned and famished dogs. The richest marks shell-wise surrounded the small estuary between Tamarindo and Las Baulas National Park, thanks to the currents. Searching this zone became a daily habit because fresh-dead shells were left on the beach at every tide. Sunburns and backaches were well repaid by finding nice Astraea buschii, Calyptraea conica, Crucibulum scutellatum, C. spinosum, colourful Clanculus and a few nice-sized Oliva polpasta. Among other shells were also hiding Trivia radians, T. pacifica and Jenneria pustulata, showing two forms : one long-shaped clear patterns, and another darker, more compact form. I also discovered Anomalocardia subrugosa, Antigona lamellaris and Pitar unicolor, of which a few recently dead specimens had kept both their valves. I had less luck with the Tellinidae because their frail ligaments do not resist waves, as those of Pitar lupanaria. My trip could have been motivated by that only shell, which I always longed to collect. Alas, I was often disappointed by spine-broken single valves. My frustration grew greater when, galloping toward waves with my surfboard, the greats outgrowths of lupanaria tested the elasticity of my feet arches’ skin. 

Troubled waters and a strong current only allowed me one snorkelling dive. On algae-covered rocks were moving around a few Cymatium pileare, Turbo saxosus and a gorgeous Conus purpurascens. I then explored sandy zones : I encountered small Heterodonax pacificus and a pretty Mactrellona exoleta, which was eaten for the aperitif. That dive was especially rewarding due to the discovery on the way back of Pitar lupanaria, live and half-buried in sand.

 The wonderful spiny shell of Pitar lupanaria

The wonderful spiny shell of Pitar lupanaria

Beach walks turned out to be at the same time enjoyable and rewarding. Gathering was made easy by the marks the molluscs left when burying themselves. Another easy method was to wait for them to emerge from the sand with the rising tide. That way, I collected Agaronia griseoalba, A. murrha and a few Hastula luctuosa of various shades. I observed great concentrations of Olivella semistriata mixed with O. gracilis and another honey-coloured Olivella species. Higher on the beach, near soft water (sewage pipes!), I collected many Donax panamensis of various colours : orange, purple, white, with or without darker stripes.

 Left to right, top to bottom:  Turbo saxosus, Opeatostoma pseudodon, Thai haemastoma, Mancinella tuberosa, Acanthina brevidentata, Vasidae sp.  Modulus cerodes, Purpura pansa, Thais speciosa, Thais haemastoma, Thais melones, Leucozonia cerata, Crassispira ostrearum  Cantharus sp., Astraea buschii, Cymatium pileare, Cymatium lignarium, Cymatium gibbosum, Cantharus sanguinolentus, Leucozonia nassa  Crassispira sp., Littorina pintado, Nerita scabricosta, Nerita chamaeleon, Clanculus cf. limbatus 4 variations, Mitra lens  Anachis fluctuata, Anachis pygmaea, Columbella major, Columbella labiosa, Mitrella guttata, Mitrella elegans, Olivella sp., Olivella gracilis, Hastula luctuosa 2 colors

Left to right, top to bottom:

Turbo saxosus, Opeatostoma pseudodon, Thai haemastoma, Mancinella tuberosa, Acanthina brevidentata, Vasidae sp.

Modulus cerodes, Purpura pansa, Thais speciosa, Thais haemastoma, Thais melones, Leucozonia cerata, Crassispira ostrearum

Cantharus sp., Astraea buschii, Cymatium pileare, Cymatium lignarium, Cymatium gibbosum, Cantharus sanguinolentus, Leucozonia nassa

Crassispira sp., Littorina pintado, Nerita scabricosta, Nerita chamaeleon, Clanculus cf. limbatus 4 variations, Mitra lens

Anachis fluctuata, Anachis pygmaea, Columbella major, Columbella labiosa, Mitrella guttata, Mitrella elegans, Olivella sp., Olivella gracilis, Hastula luctuosa 2 colors

As often, the rocky zones were of greatest interest. Basaltic plateaus south of Tamarindo often offer, depending on their exposure, a thin stripe of mobile stones of all sizes. The first shells discovered on these rocks were big Siphonaria gigas with a badly eroded dorsal side. These nice stars were easy to spot on the black stones, but didn’t cooperate much in letting go of their rock. At the same height colonies of Nerita scabricosta and Littorina pintado could be seen, hiding in stones’ faults for protection from heat. From the middle of the intertidal zone to the low tide limit, puddles were filled with hundreds of small hermit crabs. It is known that these crustaceans can gather interesting shells, sometimes rare and of good quality. This way I added to my collection a superb Phyllocoma scalariformis, three species of Murexiella, Vitularia salebrosa and a small shell I couldn’t identify, although some of its characteristics could place it in the Vasidae family. The hermit crabs also sheltered in shells of Cymatium lignarium, C. gibbosum and Leucozonia nassa, and also in smaller Aspella pyramidalis and various Epitoniidae. But crustaceans don’t always have the best taste ever, and a great majority of them were happy with Nerita shells in a bad state.

 From left to right: Opeatostoma pseudodon, Turbo saxosus and Thais haemastoma

From left to right: Opeatostoma pseudodon, Turbo saxosus and Thais haemastoma

In puddles, with the hermit crabs, I also found Nerita chamaeleon with various patterns, and a few Muricopsis zeteki. By combing sand puddles I found Conus ximenes along with four other Conus species, two Agaronia testacea, Crassispira ostrearum and Parametaria macrostoma. The rocky faults near low tide limit sheltered many Columbella labiosa and C. major, the variable Anachis fluctuata, big Chiton stokesii, perfect Pinctada margaritifera and three species of Cantharus, of which C. sanguinolentus, often very eroded. A few species lived at the bottom of those faults, sometimes buried in gravel such as the blue-eyed Turbo saxosus, Purpura pansa, Leucozonia cerata and Thais haemastoma. This Thais species shows nice shades and pattern variations, such as this dark specimen with brown stripes covered with small white spots. I also identified a Thais haemastoma floridana, whose repartition area is normally on the Caribbean coast (misidentification or travelling seashell?). My wish was to find the gorgeous gastropod Opeatostomapseudodon, a Fasciolariidae star. This species is well represented south of Tamarindo, always in pairs in deep faults with gravel bottoms. The live animal appeared to be superb : a white-veined red mantel. Unfortunately, most specimens had badly eroded whorls and many calcareous encrustations ; only a few good quality shells were found.

Exposed rocks, covered with encrusting seaweeds, offer shelter to a fauna adapted to violent waves. Here we find many Acanthina brevidentata, Thais melones, T. speciosa and Mancinella tuberosa. Under surfaces in permanent immersion were observed several species of Fissurella, Acmaea pelta and very flat Siphonaria maura with toothed aperture. S. maura is also found higher on the rocks ; the shell is then slightly more concave with a smoother aperture.

 Left to right, top to bottom:  Murexiella cf. lappa, Dermomurex obeliscus, Tripterotyphis fayae, Favartia erosa, Muricopsis zeteki, Murexiella cf. vitata  Aspella pyramidalis, Aspella cf. pollux, Vitularia cf. salebrosa, Phyllocoma scalariformis, Epitonium cf. eutaenium, Fissurella virescens, Fissurella microtrema, Siphonaria maura  Oliva polpasta, Agaronia griseoalba, Agaronia murrha, Conus purpurascens, Conus ximenes, Conus cf. brunneus  Hespererato scabriuscula, Trivia radians, Jenneria pustulata 2 patterns, Trivia sanguinea, Trivia pacifica, Calyptraea top and bottom  Pitar unicolor, Anomalocardia subrugosa, Antigona lamellaris, Heterodonax pacificus, Mactrellona exoleta, Donax panamensis  Crucibulum scutellatum bottom and top, Carditamera affinis, Siphonaria gigas top and bottom

Left to right, top to bottom:

Murexiella cf. lappa, Dermomurex obeliscus, Tripterotyphis fayae, Favartia erosa, Muricopsis zeteki, Murexiella cf. vitata

Aspella pyramidalis, Aspella cf. pollux, Vitularia cf. salebrosa, Phyllocoma scalariformis, Epitonium cf. eutaenium, Fissurella virescens, Fissurella microtrema, Siphonaria maura

Oliva polpasta, Agaronia griseoalba, Agaronia murrha, Conus purpurascens, Conus ximenes, Conus cf. brunneus

Hespererato scabriuscula, Trivia radians, Jenneria pustulata 2 patterns, Trivia sanguinea, Trivia pacifica, Calyptraea top and bottom

Pitar unicolor, Anomalocardia subrugosa, Antigona lamellaris, Heterodonax pacificus, Mactrellona exoleta, Donax panamensis

Crucibulum scutellatum bottom and top, Carditamera affinis, Siphonaria gigas top and bottom

But the richer zones are the stripes of mobile rock , generally oriented north and offering many shelters. There we found some species usually living in rocky faults, and other small molluscs. By brushing porous stones, I collected Favartia erosa, Dermomurex obeliscus and five superb Tripterotyphis fayae. When lifting stones I witnessed great concentrations of Anachis pygmaea, Mitrella elegans and M. guttata (up to ten in a square centimetre). In groups of Chama buddiana I found Modulus cerodes, small Turridae and a few Aspella. Cavities under stones were explored with a hook ; they sheltered colourful Carditamera affinis, a few dark Trivia sanguinea and Hespererato scabriuscula. In puddles, under stones on sand, I gathered some Mitra lens and saw two juvenile Cypraea cervinetta who carried on their trip after a small photocall.

In the forest : at the foot of Arenal volcano

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Buses linking both coasts are easy to find, but the journey in prehistoric vehicles driven by overheated bus drivers on bad roads is long and painful. Near San José things aren’t as bad but fares are more expensive. I shook off the road’s vibrations by stopping at the Arenal volcano, which regularly produces glowing lava flows.

The weather was much different from the pacific coast : a cloudy sky, heavy rain and stifling atmosphere. I wasn’t able to admire the Arenal’s flames, but I did explore the dense forest lying at its foot. For a few days, losing myself amongst mud and stinging plants was my lot : what a pleasure to explore such a preserved forest ! Insects were the most visible inhabitants, especially butterflies with the mythic blue Morpho. I also met various birds ; I discovered at the same time a hummingbird’s nest and the first Helicina of my journey. I am not sure of it being H. lundi ; it is variable in colour, typical specimens being white or cream. While walking throughshrubs, something got caught in my hair. Expecting a blood-drinking insect I shook it off : a little Sheldonia stayed on my hand. Soon after I found a colony of them on large leaves at 1,5 meters high. When sensing danger, these arboreals jump around while producing a "clicking" noise. I suppose they squeeze an air bubble between the mantel and the shell.

 Left to right, up to down: Sheldonia sp., Helicina cf. lundi pink, Helicina sp. 1, Helicina cf. lundi white, Helicina sp. 2, Euglandina cumingii

Left to right, up to down: Sheldonia sp., Helicina cf. lundi pink, Helicina sp. 1, Helicina cf. lundi white, Helicina sp. 2, Euglandina cumingii

In glades, under rocks and at the foot of high grasses, I found some lovely Subulina octona, often by groups approaching ten individuals. In a little riverthat showed me the way back, I collected small Melanoides tuberculata, very dark shells with pronounced protuberances.

 Left to right, up to down: Poteria cf. jamaicensis adult, Melampus coffeus, Melanoides tuberculata light and dark forms, Subulina octona, Poteria cf. jamaicensis juvenile, Helicina cf. lundi orange, white and banded forms

Left to right, up to down: Poteria cf. jamaicensis adult, Melampus coffeus, Melanoides tuberculata light and dark forms, Subulina octona, Poteria cf. jamaicensis juvenile, Helicina cf. lundi orange, white and banded forms

The Caribbean coast : between Cahuita and Puerto Viejo de Talamanca

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Tired of Arenal’s rains, I decided to reach the Caribbean coast near Cahuita. Arriving by night, I stayed in a cheap room near the National Park entrance, where started a pleasant coastal walk, nice for monkeys and sloths spotting. Near that path, by night, I observed Helicina cf. lundi in its white-lip pink form, along with juvenile specimens of Euglandina cumingii. At the park entrance, in the reception, are displayed photos of shells from the reef nearby. Most photos showed endemic Marginella I couldn’t find, because of their living in a protected area.

On the north coast of Cahuita, the rocky beach soon gives way to a black sand beach, interrupted by a fringing rocky plateau. Due to the waves and the lack of tide, I only managed to explore the supralittoral zone. However I didn’t gather in vain ; under fallen leaves, in cavities, shelter colonies of Melampus coffeus, locally collected for necklace-making. In spindrift exposed zones, the Nerita genus is very well represented with N. fulgurans, N. tesselata, big N. peloronta and the variable N. versicolor whose bright colours underline the grey of the rocks. On a cliff near the school I picked some violet-mouthed Planaxis nucleus and some Littorina nebulosa. Lower in the rocks’ crevices, little groups of Tectarius muricatus, Thais deltoidea and Purpura patula were hiding. The biggest specimen of Purpura didn’t appreciate my collecting it and strongly squirted on his aggressor. A few hours later my hands and my white T-shirt were deeply stained with purple dye that stayed for long. In shallow water, I collected Diodora listeri, Fissurella rosea and a few small Cittarium pica. No live shells were found on Playa Negra beach, but recently dead Donax denticulatus, some lovely Hyalina avena and Mulinia portoricensis with its strange foam-like periostracum. 

On my last day in Cahuita, the owner of the room I was lodging in showed me an example of wild life living around the house : a snake longer than me, hooked on a branch. Then I took the bus towards Puerto Viejo de Talamanca, a village nested around the mythical Salsa Brava wave (translate to have an idea of this reef break’s reputation !).

 From left to right: Chiton marmoratus, Chiton stokesii and Acanthopleura granulata

From left to right: Chiton marmoratus, Chiton stokesii and Acanthopleura granulata

The coast is similar to Cahuita’s and beaches are interrupted by fringing coral plateaus. South to Puerto Viejo a rocky spur creates a small protected zone, perfect for snorkelling. There I collected Hemitoma octoradiata : the animal has a red line on its foot, mantle and head. I also found Fissurella nodosa under dead coral blocks, Pinna carnea in a sandy puddle and nice variable patterned Mazatlania cosentini. In the supralittoral zone lived many Chitons such as Acanthopleura granulata, Chiton tuberculatus and the blue or green ventral-sided C. marmoratus. Nearby huge colonies of Nerita versicolor and Littorina ziczac were in their mating phase. Shallow puddles were inhabited by hundreds of Isognomon, attached by their byssus to the rocks, among which Puperita pupa and Neritina virginea, that could constitute a collection on a whole thanks to its greatly variable patterns. Tegula fasciata, with its particular labial shape and T. excavata also lived in these puddles. 

 Left to right, up to down: Nerita versicolor, Cypraea cervinetta, Littorina ziczac, Cittarium pica

Left to right, up to down: Nerita versicolor, Cypraea cervinetta, Littorina ziczac, Cittarium pica

One doesn’t have to go far from Puerto Viejo to find superb tropical forests. I was lucky enough to meet a Rastafarian who showed me a corner of paradise : an orchard abandoned for years, sheltering a wide range of never-disturbed fruits and animals. In that preserved environment I observed various intriguing species : leaf-cutting ants, tarantulas, butterflies, incredible caterpillars, birds and Dendrobates (colourful batrachians the skin of which produces a toxic substance). Most of these animals usually live in the highest levels of trees, near bromeliads. Due to the fall of some trees, these plants carried on developing near the ground with their usual fauna. There I found a magnificent orange form of Helicina cf. lundi and two other Helicina species, smaller but just as nice. In a nearby brook I collected some big light-coloured Melanoides tuberculata, finely sculpted but covered with a hard to get rid of thick green filamentous algae. Many broken snail shells lied at the foot of some trees, and that decided me to find the live animals. By digging at the feet of fig trees I found a few juvenile and adult Poteria. This lucky discovering doesn’t quite compensate my disappointment about terrestrials. Indeed expected to find more "caracoles" in such a forest. But the tropical rainforest doesn’t easily give away its secrets.

 Left to right, top to bottom:  Tectarius muricatus, Hyalina avena, Mazatlania cosentini 3 patterns, Littorina nebulosa, Littorina ziczac  Fissurella rosea top and bottom, Hemitoma octoradiata alive and bottom, Diodora listeri, Fissurella nodosa  Nerita fulgurans, Nerita peloronta, Nerita tessellata, Puperita pupa f. tristis, Neritina virginea, Planaxis nucleus  Tegula excavata, Nerita versicolor 2 patterns, Neritina virginea, Tegula fasciata, Cittarium pica  Pinna carnea, Mulinia portoricensis without and with periostracum, Donax denticulatus, Purpura patula, Thais deltoidea

Left to right, top to bottom:

Tectarius muricatus, Hyalina avena, Mazatlania cosentini 3 patterns, Littorina nebulosa, Littorina ziczac

Fissurella rosea top and bottom, Hemitoma octoradiata alive and bottom, Diodora listeri, Fissurella nodosa

Nerita fulgurans, Nerita peloronta, Nerita tessellata, Puperita pupa f. tristis, Neritina virginea, Planaxis nucleus

Tegula excavata, Nerita versicolor 2 patterns, Neritina virginea, Tegula fasciata, Cittarium pica

Pinna carnea, Mulinia portoricensis without and with periostracum, Donax denticulatus, Purpura patula, Thais deltoidea

This trip was indeed very positive,as much for the adventures I went through, in contact with nature and the Costarican people, as for my collection, improved by dozens of new species. Despite the fact that most of these shells were common, it was a pleasure to discover and observe those animals in their inhabitat, whatever their rarity ! Costa Rica deserves deeper studies, especially by scuba diving. Next time maybe ?

 

REFERENCES

R. Tucker Abbott, American seashells, Van Nostrand, Toronto, 1954

Germaine L. Warmke & R. Tucker Abbott, Caribbean seashells, Dover Publications, New York, 1962

R. Tucker Abott, Compendium of landshells, American Malacologists, Burlington, 1989

R. Tucker Abbott & S. Peter Dance, Compendium of seashells, Dutton, New York, 1982

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