Seals of the Galapagos Islands

The Galapagos archipelago has been colonized by two species of otariid, the fur seal, Arctocephalus galapagoensis , and the sea lion, Zalophus californianus wollebaeki. The former probably arrived from South America and the latter from North America, both by way of periodic incursions of colder water forming the east Pacific corridor. The terrestrial behaviour of both these otariids is affected by the high ambient temperatures in the Galapagos Patterns of breeding behaviour of otariids which lead to intense polygyny and sexual dimorphism appear to be modified. The habit of prolonging lactation, widespread in otariids, is carried to an extreme in the Galapagos fur seal. The reason for this is unclear.     

Trichomonas gallinae in columbiform birds from the Galapagos Islands

Domestic pigeons were introduced into the Galapagos Islands in 1972 or 1973. There is a high prevalence of Trichomonas gallinae among them and some evidence of canker. Trichomonas gallinae can be found also in endemic Galapagos doves in the vicinity of Puerto Ayora on Santa Cruz Island. Doves examined on pigeon-free islands were not found infected.     

Some Oceanographic Observations in the Galapagos Islands

The oceanographic conditions that obtained during the periodof study are described. The study area is characterized by surfacetemperatures near 20°C and a sharp thermocline at a depthof 40 m. The temperature below 1000 m is less than 5°C.An episode of upwelling occurred during the period of study.The upwelled water was displaced by water characteristic ofthat found north of the Equatorial Front. The approximate positionof the Equatorial Front during the study period was 00°15' S latitude.     

Amphipod crustaceans from anchihaline cave waters of the Galapagos Islands

Three species of blind Amphipoda are recorded from anchihaline cave waters in the Galapagos Islands. One of these, Galapsiellus leleuporum (Monod, 1970) was previously know from the islands; the male is described for the first time. The other two belong to families with predominantly (though not exclusively) deep-sea members: Valettietta cavernicola sp. nov. (family Lysianassidae; and Antronicippe serrata gen. et sp. nov. (family Pardaliscidae). The genus Valettietta was not previously recorded from caves; it contained two abyssal species in the Atlantic, while a third species was recorded from the Pacific in a vertical haul between 0 and 5300 m. Antronicippe is closely related to Spelaeonicippe , a genus with two species known from anchihaline caves in the Canary Islands and the West Indies.     

Cuticular hydrocarbons of grasshoppers from the Galapagos Islands, Ecuador

Cuticular lipids of adult Schistocerca literosa, Schistocerca melanocera and Halmenus robustus were analyzed. They have a similar range of hydrocarbons to those previously reported for other grasshoppers, but contain significant amounts of squalene which has not previously been reported from grasshopper cuticle. In Halmenus, squalene comprises 17% of the total hydrocarbons, while internally branched methylalkanes are present in much smaller quantities than in other grasshoppers. The results lend no support for a close taxonomic link between Halmenus and Schistocerca.     

Amphipod crustaceans from anchihaline cave waters of the Galapagos Islands

Three species of blind Amphipoda are recorded from anchihaline cave waters in the Galapagos Islands. One of these, Galapsiellus leleuporum (Monod, 1970) was previously know from the islands; the male is described for the first time. The other two belong to families with predominantly (though not exclusively) deep-sea members: Valettietta cavernicola sp. nov. (family Lysianassidae; and Antronicippe serrata gen. et sp. nov. (family Pardaliscidae). The genus Valettietta was not previously recorded from caves; it contained two abyssal species in the Atlantic, while a third species was recorded from the Pacific in a vertical haul between 0 and 5300 m. Antronicippe is closely related to Spelaeonicippe, a genus with two species known from anchihaline caves in the Canary Islands and the West Indies.     

110 years of Avipoxvirus in the Galapagos Islands

The role of disease in regulating populations is controversial, partly owing to the absence of good disease records in historic wildlife populations. We examined birds collected in the Galapagos Islands between 1891 and 1906 that are currently held at the California Academy of Sciences and the Zoologisches Staatssammlung Muenchen, including 3973 specimens representing species from two well-studied families of endemic passerine birds: finches and mockingbirds. Beginning with samples collected in 1899, we observed cutaneous lesions consistent with Avipoxvirus on 226 (6.3%) specimens. Histopathology and viral genotyping of 59 candidate tissue samples from six islands showed that 21 (35.6%) were positive for Avipoxvirus, while alternative diagnoses for some of those testing negative by both methods were feather follicle cysts, non-specific dermatitis, or post mortem fungal colonization. Positive specimens were significantly nonrandomly distributed among islands both for mockingbirds (San Cristobal vs. Espanola, Santa Fe and Santa Cruz) and for finches (San Cristobal and Isabela vs. Santa Cruz and Floreana), and overall highly significantly distributed toward islands that were inhabited by humans (San Cristobal, Isabela, Floreana) vs. uninhabited at the time of collection (Santa Cruz, Santa Fe, Espanola), with only one positive individual on an uninhabited island. Eleven of the positive specimens sequenced successfully were identical at four diagnostic sites to the two canarypox variants previously described in contemporary Galapagos passerines. We conclude that this virus was introduced late in 1890's and was dispersed among islands by a variety of mechanisms, including regular human movements among colonized islands. At present, this disease represents an ongoing threat to the birds on the Galapagos Islands.     

Breeding seasons of sea-birds in the Galapagos Islands

The sea-birds breeding in the Galapagos Islands show a diversity of breeding cycles. Some species have rigidly fixed annual breeding while others breed throughout the year but have peaks of breeding at less than annual intervals. The eight species which have non-annual breeding are probably breeding as often as possible with the interval between the end of a breeding attempt and the start of the next being the time needed to moult the wing and tail feathers. Only one species is definitely known to breed and moult at the same time.
Although there are well marked seasonal fluctuations in the sea temperature, regular sampling failed to demonstrate any regular fluctuations in the surface plankton. The available evidence suggests that food for some sea-birds is erratic and unpredictable. Some non-annual breeding species have their breeding synchronized by severe food shortages which delay breeding, presumably because females cannot find enough food to form eggs, until conditions improve.
Timing of the breeding season in annual breeders is less easily explained but some species may be feeding well away from the islands in areas where there is a regular fluctuation in the food supply. Most of the annual breeders have prolonged breeding seasons and in two species breeding is out of phase on different islands. Perhaps species are influenced by some weak annual variation in food supply which makes it disadvantageous to breed in a few months of the year.     

Anchialine podocopid Ostracoda of the Galapagos Islands

Water-filled fissures and lava tubes on Isla Santa Cruz and Isla Isabela provide anchialine habitats for 11 species of podocopid and platycopid Ostracoda, most with Atlantic and West Indian affinities. Their ancestors may have been carried to earlier islands in the Galapagos system by trans-Isthmian currents, on vegetation or larger animals, or by migrating waterfowl. None are derived from present-day Pacific coastal faunas of North, Central or South America. Two species of Cytheracea, a new species of Anchistrocheles (Bairdiacea), and one of Cytherella (Platycopida) are described.     

Marine Ostracoda of the Galapagos Islands and Ecuador

Marine algae collected from rock pools on Hood, Fernandina and Mosquera, in the Galapagos Islands, have provided a fauna of 26 ostracod species of which 14 are new. One genus, belonging to the Hemicytheridae, is also new and appears to be endemic to the Islands. From two littoral algal samples collected from Punta Canoa and San Pedro beach, Ecuador, an assemblage of some nine species, four of which are new, is also described. Two ostracods: Touroconcha lapidiscola and Loxoconcha (Lox-ocorniculum) lenticuloides , are the only species so far known to be present both in the Galapagos Islands and off the coast of Central and South America. One species: Cytherelloidea praecipua recorded from off Tobago and Clipperton Islands may be present in the Galapagos but this has not definitely been confirmed. The evolution in the Gulf Coast/Caribbean region of several ostracods and their subsequent dispersal westwards is discussed.     

New records of ahermatypic scleractinian corals from the Kuril Islands

Four species of caryophyllid scleractinians, Caryophylla ambrosia, C. scobinosa, C. alaskensis, and Polymyces montereyensis, were recorded for the first time in the Sea of Okhotsk off the Kuril Islands. These findings extend the range for the species, of which three had previously been considered to be restricted to the tropical and warm Indopacific waters. These data will supplement regional reports on the bottom fauna of the most fertile and extensively commercially exploited continental shelf region of the North Pacific.Original Russian Text Copyright © 2004 by Biologiya Morya, Latypov.     

A summary of geographical characteristics of the Galapagos Islands

Republished here, with permission, in a slightly modified form, from Noticias de Galapagos 55, July 1995, 18–24. Copyright remains, by agreement, with Noticias de Galápagos , which is published by The Charles Darwin Foundation for the Galápagos Islands.     

Species number,area and habitat diversity in the Galapagos Islands

The Galapagos vascular plant species are divided into two groups, showing preferences for dry and wet habitats. This division is based on the results of a phytosociological study and is not influenced by such factors as island area, elevation, climate or soil types. The different distribution patterns of the dry and wet species are discussed and it is concluded that habitat diversity offers a better explanation for species numbers and distribution patterns than do island size and isolation. Claims that a dynamic MacArthur-Wilson type equilibrium has been reached for vascular plants in the Galapagos archipelago seem premature.     

Snorkeler damage to reef corals in the Maldive Islands

Rapid and intensive survey methods were used to measure coral breakage by snorkelers on a Maldivian resort reef. On the most impacted section of reef, breakage over a one month period was estimated at 17% of susceptible coral cover and 7% of total coral cover.     

The distribution of mosquitoes across an altitudinal gradient in the Galapagos Islands

An avian malaria parasite (genus Plasmodium) has been detected consistently in the Galapagos Penguin (Spheniscus mendiculus) and less frequently in some passerines. We sampled three resident mosquito species (Aedes taeniorhynchus, Culex quinquefasciatus, and Aedes aegypti) using CDC light and gravid traps on three islands in 2012, 2013, and 2014. We sampled along altitudinal gradients to ask whether there are mosquito‐free refugia at higher elevations as there are in Hawaii. We captured both Ae. taeniorhynchus and Cx. quinquefasciatus at all sites. However, abundances differed across islands and years and declined significantly with elevation. Aedes aegypti were scarce and limited to areas of human inhabitation. These results were corroborated by two negative binomial regression models which found altitude, year, trap type, and island as categorized by human inhabitation to be significant factors influencing the distributions of both Ae. taeniorhynchus and Cx. quinquefasciatus. Annual differences at the highest altitudes in Isabela and Santa Cruz indicate the lack of a stable highland refuge if either species is found to be a major vector of a parasite, such as avian malaria in Galapagos. Further work is needed to confirm the vector potential of both species to understand the disease dynamics of avian malaria in Galapagos.     

Spirorbinae (Polychaeta: Serpulidae) of the Galapagos Islands*

Twelve species, six of which are new, are recorded from shores andshallow water. The most generally abundant are Spirorbis tricornigerus Rioja, S. bushi Rioja (both dextral with tube incubation), S. regalis sp. n., S. tuberculatus sp. n. (both sinistral with opercular incubation) and S. placophora sp. n. (sinistral, with tube incubation). Other sinistral species include S. claparedei Caullery & Mesnil, S. berkeleyana Rioja, S. bidentatus sp. n., and S. translucens sp. n. Dextral species include S. marioni Caullery & Mesnil, S. pagenstecheri Quatrefages and S. unicornis sp. n. The new species mentioned above have been described by the author named first.
The Spirorbis fauna seems to be quite like that of Mexico and S. America, from which repeated introductions have probably occurred, perhaps on stones buoyed by seaweeds and drifting on the Peruvian and El Nino currents. Its considerable diversity is not attributed to speciation within the archipelago.     

Four new species of Isospora from the small tree finch (Camarhynchus parvulus) from the Galapagos Islands

Four isosporan species are described from the small tree finch, Camarhynchus parvulus from Isabela Island on the Galapagos Archipelago. Isospora exigua n. sp. oocysts subspheroidal, one-layered, smooth, yellow-brown color, 20.4 X 20.1 (20-23 X 18-23) microns, with no micropyle, residuum, or polar body. Sporocysts ovoidal, 14 X 9.5 (13-15 X 8-10) microns, with small Stieda and substieda bodies and irregular-shaped residuum. Isospora rotunda n. sp. oocysts subspheroidal, single-layered, smooth, yellow-brown wall with large polar body and no micropyle or residuum, 20.9 X 20.8 (20-24 X 19-23) microns. Sporocysts ovoidal, 15 X 9.7 (13-16 X 9-10) microns with knob-like Stieda bodies, prominent substieda bodies and round residuum. Isospora fragmenta n. sp. oocysts subspheroidal with no micropyle or residuum but with many splinter-like polar granules and a smooth, colorless, single-layered wall, 25.3 X 24.2 (24-27 X 23-25) microns. Sporocysts piriform 15.4 X 11.5 (14-17 X 11-12) microns with knob-like Stieda bodies, prominent substieda bodies, and irregular-shaped residuum. Isospora temeraria n. sp. oocysts ellipsoidal with one polar body, no micropyle or residuum, and wall of a single layer, smooth, yellow-brown color, 25.4 X 21.1 (21-30 X 17-23) microns. Sporocysts piriform, 15 X 10 (14-15 X 9-11) microns with knob-like Stieda bodies, prominent substieda bodies, and a round residuum. One woodpecker finch, Cactospiza pallida, was found to be infected with I. exigua, and a warbler finch, Certhidea olivacea was infected with I. fragmenta.     

Free-living scleractinian corals on reefs of the Seychelles Islands

Thirty-nine species of unattached scleractinian corals that belong to 22 genera of 9 families were found on the Seychelles reefs. Variations of the colony form of corals living on soft sediments under continuous wave action are described. Irrespective of their initial growth form and taxonomic position, corals assume a form close to spherical. Because of the worldwide deterioration of coral reefs, the adaptation to changing ecological conditions by reef-building corals needs to be studied.     

Four New Species of Isospora from the Small Tree Finch (Camarhynchus parvulus) from the Galapagos Islands1

ABSTRACT. Four isosporan species are described from the small tree finch, Camarhynchus parvulus from Isabela Island on the Galapagos Archipelago. Isospora exigua n. sp. oocysts subspheroidal, one-layered, smooth, yellow-brown color, 20.4 × 20.1 (20-23 × 18-23) μm, with no micropyle, residuum, or polar body. Sporocysts ovoidal, 14 × 9.5 (13-15 × 8-10) μm, with small Stieda and substieda bodies and irregular-shaped residuum. Isospora rotunda n. sp. oocysts subspheroidal, single-layered, smooth, yellow-brown wall with large polar body and no micropyle or residuum, 20.9 × 20.8 (20-24 × 19-23) μm. Sporocysts ovoidal, 15 × 9.7 (13-16 × 9-10) μm with knob-like Stieda bodies, prominent substieda bodies and round residuum. Isospora fragmenta n. sp. oocysts subspheroidal with no micropyle or residuum but with many splinter-like polar granules and a smooth, colorless, single-layered wall, 25.3 × 24.2 (24-27 × 23-25) μm. Sporocysts piriform 15.4 × 11.5 (14-17 × 11-12) μm with knob-like Stieda bodies, prominent substieda bodies, and irregular-shaped residuum. Isospora temeraria n. sp. oocysts ellipsoidal with one polar body, no micropyle or residuum, and wall of a single layer, smooth, yellow-brown color, 25.4 × 21.1 (21-30 × 17-23) μm. Sporocysts piriform, 15 × 10 (14-15 × 9-11) μm with knob-like Stieda bodies, prominent substieda bodies, and a round residuum. One woodpecker finch, Cactospiza pallida, was found to be infected with I. exigua, and a warbler finch, Certhidea olivacea was infected with I. fragmenta.