The visual biology of Hawaiian reef fishes was explored by examining their eyes for spectral sensitivity of their visual pigments and for transmission of light through the ocular media to the retina. The spectral absorption curves for the visual pigments of 38 species of Hawaiian fish were recorded using microspectrophotometry. The peak absorption wavelength (λ_max) of the rods varied from 477–502 nm and the λ_max of individual species conformed closely to values for the same species previously reported using a whole retina extraction procedure. The visual pigments of single cone photoreceptors were categorized, dependent on their λ_max-values, as ultraviolet (347–376 nm), violet (398–431 nm) or blue (439–498 nm) sensitive cones. Eight species possessed ultraviolet-sensitive cones and 14 species violet-sensitive cones. Thus, 47% of the species examined displayed photosensitivity to the short-wavelength region of the spectrum. Both identical and nonidentical paired and double cones were found with blue sensitivity or green absorption peaks (> 500 nm).

Spectrophotometry of the lens, cornea, and humors for 195 species from 49 families found that the spectral composition of the light transmitted to the retina was most often limited by the lens (73% of species examined). Except for two unusual species with humor-limited eyes, Acanthocybium solandri (Scombridae) and the priacanthid fish, Heteropriacanthus cruentatus, the remainder had corneal-limited eyes. The wavelength at which 50% of the light was blocked (T50) was classified according to a system modified from Douglas and McGuigan (1989) as Type I, T50 <= 355 nm, (32 species); Type IIa, 355 < T50 <= 380 nm (30 species); Type IIb, 380 < T50 <= 405 nm (53 species) and Type III, T50 > 405 nm (84 species). Possession of UV-transmitting ocular media follows both taxonomic and functional lines and, if the ecology of the species is considered, is correlated with the short-wavelength visual pigments found in the species.

Three types of short-wavelength vision in fishes are hypothesized: UV-sensitive, UV-specialized, and violet-specialized. UV-sensitive eyes lack UV blockers (Type I and IIa) and can sense UV light with the secondary absorption peak or beta peak of their longer wavelength visual pigments but do not possess specialized UV receptor cells and, therefore, probably lack UV hue discrimination. UV-specialized eyes allow transmission of UV light to the retina (Type I and IIa) and also possess UV-sensitive cone receptors with peak absorption between 300 and 400 nm. Given the appropriate perceptual mechanisms, these species could possess true UV-color vision and hue discrimination. Violet-specialized eyes extend into Type IIb eyes and possess violet-sensitive cone cells.

UV-sensitive eyes are found throughout the fishes from at least two species of sharks to modern bony fishes. Eyes with specialized short-wavelength sensitivity are common in tropical reef fishes and must be taken into consideration when performing research involving the visual perception systems of these fishes. Because most glass and plastics are UV-opaque, great care must be taken to ensure that aquarium dividers, specimen holding containers, etc., are UV-transparent or at least to report the types of materials in use.

The colors of 51 species of Hawaiian reef fish have been measured using a spectrometer and therefore can be described in objective terms that are not influenced by the human visual experience. In common with other known reef fish populations, the colors of Hawaiian reef fish occupy spectral positions from 300–800nm; yellow or orange with blue, yellow with black, and black with white are the most frequently combined colors; and there is no link between possession of ultraviolet (UV) reflectance and UV visual sensitivity or the potential for UV visual sensitivity. In contrast to other reef systems, blue, yellow, and orange appear more frequently in Hawaiian reef fish. Based on spectral quality of reflections from fish skin, trends in fish colors can be seen that are indicative of both visually driven selective pressures and chemical or physical constraints on the design of colors. UV-reflecting colors can function as semiprivate communication signals. White or yellow with black form highly contrasting patterns that transmit well through clear water. Labroid fishes display uniquely complex colors but lack the ability to see the UV component that is common in their pigments. Step-shaped spectral curves are usually long-wavelength colors such as yellow or red, and colors with a peak-shaped spectral curves are green, blue, violet, and UV.

In the previous two papers in this three-part series, we have examined visual pigments, ocular media transmission, and colors of the coral reef fish of Hawaii. This paper first details aspects of the light field and background colors at the microhabitat level on Hawaiian reefs and does so from the perspective and scale of fish living on the reef. Second, information from all three papers is combined in an attempt to examine trends in the visual ecology of reef inhabitants. Our goal is to begin to see fish the way they appear to other fish. Observations resulting from the combination of results in all three papers include the following. Yellow and blue colors on their own are strikingly well matched to backgrounds on the reef such as coral and bodies of horizontally viewed water. These colors, therefore, depending on context, may be important in camouflage as well as conspicuousness. The spectral characteristics of fish colors are correlated to the known spectral sensitivities in reef fish single cones and are tuned for maximum signal reliability when viewed against known backgrounds. The optimal positions of spectral sensitivity in a modeled dichromatic visual system are generally close to the sensitivities known for reef fish. Models also predict that both UV-sensitive and red-sensitive cone types are advantageous for a variety of tasks. UV-sensitive cones are known in some reef fish, red-sensitive cones have yet to be found. Labroid colors, which appear green or blue to us, may be matched to the far-red component of chlorophyll reflectance for camouflage. Red cave/hole dwelling reef fish are relatively poorly matched to the background they are often viewed against but this may be visually irrelevant. The model predicts that the task of distinguishing green algae from coral is optimized with a relatively long wavelength visual pigment pair. Herbivorous grazers whose visual pigments are known possess the longest sensitivities so far found. “Labroid complex colors” are highly contrasting complementary colors close up but combine, because of the spatial addition, which results from low visual resolution, at distance, to match background water colors remarkably well. Therefore, they are effective for simultaneous communication and camouflage.

The appearance of an organism's color pattern is a function of numerous variables, including the background on which the organism is observed. Hence, color patterns that appear similar or conspicuous when taken out of context, may, in reality, appear quite different when viewed in a natural setting. I investigated the relative conspicuousness of chuckwallas, Sauromalus obesus (= ater) among three populations in which males differ in their coloration. The color pattern of male and female chuckwallas was compared to the background color of rocks on which individuals were observed basking or displaying. Data were also collected on predation pressures and the thermal environment to see whether there was any association with conspicuousness. Male tail and body conspicuousness, and female tail conspicuousness, varied among the three populations. In all populations, male tail color was more conspicuous than male body color and, within all populations, males were more conspicuous than females. However, males and females were not equally conspicuous among populations; females from one population were as conspicuous as males from a different population. Conspicuousness appeared to be negatively associated with predation pressures. Little evidence was found to suggest that thermal considerations influenced color variation among the three populations. The role of chuckwalla conspicuousness is also discussed in the context of sexual selection.

We used protein electrophoresis of the allozyme products of 21 gene loci to examine relationships among five western species of the Macrhybopsis aestivalis complex (sensu Eisenhour, 1997), with emphasis on three species recognized from morphology in the Red and Arkansas river basins. Monophyly was supported for both species endemic to those basins, M. australis in the Red and M. tetranema, in the Arkansas. However, support was weak because of high genetic similarity between these species and the more wide-ranging species, M. hyostoma. Within the Arkansas and Red river basins, only 2% and 5%, respectively, of total genic diversity was attributable to differences between the endemic species and M. hyostoma. Across all samples from the two basins, only 14% of total diversity was attributable to among-species differences. Phenetic and allele-frequency parsimony analyses grouped M. hyostoma from the Red and Arkansas river basins with the associated endemic in the respective basin rather than with populations of M. hyostoma from elsewhere. The results are consistent with the indication from morphology that M. tetranema and M. australis are sister species, if it is assumed that the present patterns of allozyme variation are a result of subsequent contact and introgressive hybridization with M. hyostoma. Collections of M. aestivalis from the Rio Grande Basin and M. marconis from the San Marcos River Basin were markedly divergent from each other and from other members of the complex.

The extension and retraction of the throat fan or dewlap is one of the most conspicuous aspects of the display behavior of male Anolis lizards. We explored aspects of the functional significance of displaying the male's dewlap by surgically preventing male brown anoles (Anolis sagrei) from extending their dewlaps and comparing their behavior with controls that could extend their dewlaps. In 30-min laboratory contests, we compared the display behavior of untreated males paired with either experimental males or with sham-treated control males. In a subsequent field study, we tested what effect displaying the dewlap has on male residence time (days males remained at a site), visibility (number of sightings of males), maximum distance moved (from site of release), home range size, and body size during 18 censuses over a 47-day period. Untreated males paired with the two types of stimulus males in the laboratory study did not differ significantly in latency to display, number of dewlap extensions, number of bobbing displays, number of bobbing displays with dewlap extensions, or in proportion of males erecting crests in both short distance physical encounters (< 0.6 m) and in visual encounters at 1 m and 3 m. Thus, males did not modify their display behavior based on whether their opponents extended their dewlaps. In the field study, experimental and control males did not differ significantly in residence time, visibility, maximum distanced moved, and home-range size. In addition, males in the two treatment groups captured at the end of the study did not differ in snout–vent length or body mass. These results provide no evidence for a functional significance of the displaying of the male's dewlap in A. sagrei.

Etheostoma virgatum has been treated as a species occupying three widely separated regions of the Cumberland River drainage in Kentucky and Tennessee. To test the hypothesis that the three widely disjunct populations of E. virgatum are monophyletic, DNA sequence data from mitochondrial and nuclear loci were gathered on E. virgatum and other species of Catonotus including all species of barcheek darters. Morphological data were analyzed from populations throughout the range of E. virgatum. The three widely separated populations of E. virgatum, although morphologically similar, do not form a monophyletic group in phylogenetic analyses of molecular data. Consistent with this result, two of the populations are described as new species. These three species had been identified as E. virgatum because of the shared presence of bold dark stripes along the side of the body, a feature not found in the other four species of barcheeks. It is unclear whether the presence of bold stripes represents retention of a pleisiomorphic trait (lost in other barcheeks) or whether the condition arose independently in these three species.

Existing studies indicate that multiple physical habitat characteristics can affect the abundance and distribution of larval stream salamanders. We quantified seasonal patterns of microhabitat use by larval southern two-lined salamanders (Eurycea cirrigera) and microhabitat availability in two Georgia Piedmont streams from April 2000 to April 2001. Larvae were generally significantly underrepresented in deep areas with low percentages of coarse substratum, locations dominated by bedrock substrata, and areas lacking debris (November sample only). Both between-stream differences in microhabitat use and within-stream seasonal differences in microhabitat use generally reflected differences in microhabitat availability. The close association of larval two-lined salamanders with substrata that provided cover indicates that habitat heterogeneity is important for this species. Consequently, loss of habitat complexity through anthropogenic disturbance may result in decreases in abundance of southern two-lined salamanders in Georgia.

The early life history of the conger eel, Conger oceanicus, has been the focus of only a few studies. These have emphasized larval development and distribution; little is known about its metamorphosis and settlement. To quantify changes in body proportions, dentition, and pigmentation of metamorphosing C. oceanicus during these transitions, we collected leptocephali, glass eels, elvers, and juveniles during 1993, 1996, and 1998 (n = 166) in coastal ocean and estuarine waters in southern New Jersey. We developed a staging scheme based on morphology, pigmentation, and dentition that categorized the developmental state from the leptocephalus to the juvenile stage. Our study demonstrated that, although the early life history of C. oceanicus occurs over large spatial scales (10,000s of km²), metamorphosis can take place over only a few 10s of km². We conclude that selected body proportions (e.g., percent preanal length) are better indicators of developmental state than total length for metamorphosing C. oceanicus. Our results also suggest that certain metamorphic stages are associated with specific habitats. Further, the spatial differences in morphology, dentition, and developmental stage across the ocean to estuary transect suggest that oceanic individuals are earlier in development than those caught within the estuary and that many aspects of metamorphosis (e.g., changes in body morphology, dentition, and habitat use) co-occur with their migration into estuaries.

We investigated the use of the pelvic fins for locomotion along the bottom in the little skate, Leucoraja erinacea by video recording locomotor behavior of skates both in the field and in captivity and by examining various anatomical preparations of their pelvic fins. An external notch or concavity in the lateral margin of the pelvic fins partially separates each fin into anterior and posterior lobes. The skeletal elements and musculature of the anterior lobe are highly modified and comprise a functionally distinct appendage (the crus) that possesses three flexible joints. Locomotion of skates along the bottom is almost always due to the exclusive activity of the crura of the pelvic fins pushing off the substrate synchronously to generate thrust. The skate then glides through the water a short distance as the crura are repositioned for the next thrust phase. This type of thrust and glide locomotion is called punting. We conclude that punting is a significant form of locomotion suited to the benthic lifestyle of skates.

A new species of the previously monotypic loricariid subfamily Lithogeninae is described from northern Venezuela. Lithogenes valencia is the first representative of the subfamily to be discovered subsequent to the discovery and description of Lithogenes villosus Eigenmann, 1909, from Guyana and extends the geographic distribution of the subfamily beyond the Guyana Shield region of northeastern South America. The new species shares several derived features with L. villosus that are not observed among other Loricariidae. It is diagnosed from L. villosus by the broader head, 27–29% SL (vs 22% SL), 25–29 premaxillary teeth (vs 9–10), the presence of nine (vs 8) branched pectoral-fin rays, anal fin rays ii,5 (vs ii,7), straight (vs sickle-shaped) lateropterygium, and by the presence of small plates in the dorsal and ventral series of the lateral trunk irregularly arranged and not contacting the plates of the median series (vs plates larger, regularly arranged in series, in contact with the median series plates posteriorly). Lithogenes valencia is known only from six specimens collected from the basin of Lago de Valencia, an endorrheic lake basin occupying a tectonic graben situated between the coastal and interior ranges of the Cordillera de La Costa of north-central Venezuela. Subsequent collecting efforts have failed to obtain additional specimens and the species may now be extinct, since the lake and its tributaries have become severely degraded by pollution and disturbance. Aspects of its peculiar morphology are described and illustrated, and we provide evidence for its sister-group relationship to L. villosus. Presently isolated and undergoing rapid desiccation and contamination, Lago de Valencia had a recent connection with the Orinoco River to the south. Although dispersal into the lake basin via this relatively recent connection is possible, it is argued instead that consideration of its habitat and phylogenetic position as a basal representative of the Loricariidae indicate that a more ancient biogeographic explanation may be responsible for its unexpected occurrence in the northern Caribbean coastal region.

Analysis of 27 standard and truss measurements, 15 meristic characters, and coloration of the Etheostoma pyrrhogaster species complex across its range supported the recognition of two allopatric and diagnosable species within this complex. The previously described E. pyrrhogaster and Etheostoma cervus, a new species described herein, are endemic to the Obion and Forked Deer River systems, respectively, in western Kentucky and Tennessee. The two species differ in pigmentation of nuptial males with E. pyrrhogaster having extensive turquoise pigmentation in dorsal, anal, and pelvic fins, whereas E. cervus lacks extensive turquoise pigmentation in these fins. The ventral portion of the head of nuptial male E. pyrrhogaster has a green cast, whereas this area in nuptial male E. cervus is straw colored. Lateral-line scales are modally 42 in E. pyrrhogaster and 39 in E. cervus. Interorbital width and body depth are also greater in E. pyrrhogaster than in E. cervus.

A new species of Creagrutus is described from the western portions of the Rio Uaupés basin near the Brazilian-Colombian border region. The species is most closely related to, and most similar externally to, Creagrutus amoenus and Creagrutus kunturus, but differs from those species in details of pigmentation, meristics, and morphometrics.

Hisonotus insperatus, new species, is distinguished from all the other species of the genus Hisonotus Eigenmann and Eigenmann by the combination of a pair of rostral plates at the tip of the snout, the complete median plate series to base of the caudal fin, a lateral line that is continuous along the middle of the body, a pectoral spine smooth and lacking odontodes along its posterior dorsal margin for a distance more than one-half of its width, and a scapular bridge that is completely exposed, sometimes with a very reduced median pair of arrector fossae.

Population structure of the California grunion, Leuresthes tenuis, was asssessed by examining patterns of allozymic variation. Six specimens from each of four southern California locations (Goleta, Malibu, San Pedro, and Imperial Beach) were examined electrophoretically for the gene products of 55 presumptive loci; nine loci were found to be polyallelic. Direct-count heterozygosity averaged 0.036. A total of 50 specimens from each of the four locations was scored for the gene products of the nine polyallelic loci. A conservative significance test using exact probabilities showed that all four samples individually agreed with Hardy-Weinberg expectations. Few private alleles were detected, and Nei's genetic distances between pairs of samples were negligible. F-statistics were not significantly different from zero. However, a contingency chi-square test including all four geographic samples falsified the null hypothesis of no significant difference among the samples (P = 0.038). A Mantel test showed a significant correlation between geographic distance and Cavalli-Sforza and Edwards' chord distance matrices. The population structure approximates panmixia but also contains some indication of isolation by distance.

A chytrid fungus, Batrachochytrium dendrobatidis, was found in salamanders, Ambystoma tigrinum stebbinsi, collected in southern Arizona, USA. The chytrid was isolated and cultured, and Koch's postulates were satisfied by infection of metamorphosed salamanders with pure culture and subsequent reisolation from these salamanders. We used the salamander strain and a strain isolated from lowland leopard frogs in Arizona, Rana yavapaiensis, to infect metamorphosed A. tigrinum, R. yavapaiensis, and R. boylii. All three species became infected, but none of the infected salamanders died within 60 days, and mortality of infected frogs did not differ significantly from controls, although sample size was small. Chytrid infection could not be detected by light histology in most of the infected frogs and one of the infected salamanders 60 days after infection. To date, there are three records of chytridiomycosis in salamanders on websites; ours is the first complete report of occurrence and pathology of chytridiomycosis in field-collected North American salamanders. Our results also demonstrate that chytridiomycosis does not always lead to mortality. Individuals within a species vary in susceptibility to infection, animals appear to recover from the infection, and syntopic salamanders and frogs may act as reciprocal pathogen reservoirs for chytrid infections.

Comparisons of cardinalfish (Apogonidae) assemblage structure were made using small rotenone samples within specific habitats from Belize, Honduras, and Puerto Rico in the Atlantic Ocean, and the Hawaiian Islands in the Pacific Ocean. A total of 146 collections containing two or more apogonid species was made in the Gulf of Honduras, 22 in Puerto Rico, and 35 in the Hawaiian Islands. Detrended correspondence analysis determined whether collections from specific habitats clustered together in ordination space. Analysis of the Atlantic apogonid data did not result in the recognition of any exclusive assemblages corresponding to specific habitats, whereas collections from the Pacific Ocean demonstrated exclusive clusters of cardinalfish assemblages from different habitats. Horn's Index of Similarity was used to compare assemblages, and a randomization test was used to evaluate their significance. Because these differences could be the result of large differences in sample sizes between collections from the two oceans, subsamples of the much larger Atlantic dataset were taken. The subsamples demonstrated that with smaller samples the probability of visualizing polygons containing only samples from a single habitat are greater, but these samples did not result in the same level of habitat specificity as found for the Pacific samples, and similarity measures also differed. These data demonstrate for the first time that assemblage patterns within a single fish family differ between the Pacific and Atlantic Oceans. This difference and earlier findings that different fish families exhibit various levels of associations of assemblages with habitats, support the conclusion that assemblage structure of coral-reef fishes cannot be explained by a single paradigm.

Current theories on the alternative mating tactics suppose that individuals may opt for particular behavioral patterns depending of their morphological status. Facultative paedomorphosis in newts and salamanders is a suitable process to explore this question because it implies the coexistence of two different morphological morphs differing by the presence of gills and epigamic traits. The aim of this study was to find out whether paedomorphs and metamorphs use similar tactics to attract mates in the presence of a rival and whether there are differences in sexual activity and success between alternative morphs. Sexual interactions in triadic encounters were staged and analyzed in a standardized experimental design. The two kinds of males did not differ in terms of sexual activity, spermatophore deposition or female responsiveness. Both rival paedomorphic and metamorphic males exhibited sexual interference, but in most encounters, intruders just disturbed the courting pair. Sperm transfer success was lower in triadic encounters than in dyadic encounters. These results illustrate that intermorph breeding also occurs in the presence of competitors but that the success rate of the newts is considerably decreased in such competitive situations. Moreover, newts do not use alternative reproductive tactics depending on their status (i.e., paedomorph or metamorph).

Phylogenetic analyses of cytochrome b sequences support the prior hypothesis from genetic and meristic data that the Ozark Plateau endemic, Cottus hypselurus, is polytypic. These results support recognition of two species, C. hypselurus (Osage, Gasconade and Black Rivers) and Cottus sp. cf. hypselurus (Current, Eleven Point, Spring, and White rivers).

Coordinated terrestrial movement has not previously been reported in crocodilians. However, between 1989 and 1999, 94% of 525 Caiman crocodilus yacare found on land in the Pantanal were in coordinated groups (n = 73) walking head to tail and forming nearly straight lines. Caimans left pools and initiated terrestrial movements spontaneously and in response to disturbance by researchers and hunters. The sex ratio of the groups was biased toward males (0.8 ± 0.24) and was similar to that found in aquatic habitats in the study area. However, two groups consisted only of females. When caimans left pools subjected to disturbances, such as hunting and capture for research, they walked head to tail in lines. Caimans that left pools in response to disturbance buried in mud near pools or in leaf litter in forest.

Riverine fishes may benefit from moving onto inundated floodplains and directly exploiting floodplain resources. Studies of floodplain ecology for smaller streams have focused primarily on how fishes benefit indirectly from flooding (e.g., cycling of allochthonous nutrients). In a second order, blackwater stream in southern Mississippi, more food was available for cherryfin shiners (Lythrurus roseipinnis) on an inundated floodplain than was available in the low water stream. The floodplain drift of prey items consisted of significantly higher densities of terrestrial arthropods (Collembola, terrestrial Acariformes) and aquatic organisms associated with floodplain pools (Oligochaeta, larval Chironomidae, Anomopoda). While on the floodplain, L. roseipinnis ate significantly more food and consumed a significantly different diet than did L. roseipinnis in the stream. The difference in diets between the two habitats was because of the predominance of a terrestrial arthropod (Collembola) in the diet of L. roseipinnis on the floodplain. These results demonstrate that fishes in small streams can directly exploit floodplain food resources of briefly inundated floodplains. If stream-floodplain connectivity is eliminated in small streams through anthropogenic activities (e.g., channelization, riparian destruction), then L. roseipinnis and other small stream fishes will have limited access to invertebrate food resources.

Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala) eggs and whether crayfish presence induces a change in the timing of hatching of R. sphenocephala eggs. We found that crayfish significantly reduce the hatching success of R. sphenocephala eggs by eating them and that eggs hatch significantly faster in the presence of crayfish than when crayfish are not present. We also found that the nonlethal presence of crayfish (caged with no access to eggs) induced accelerated hatching, indicating that injured conspecifics are not required to elicit the response. Reception of chemical cues produced or released by crayfish may play an important role in survival of R. sphenocephala eggs.

In a laboratory experiment, we investigated the effects of low pH environment, a key parameter of acidity, on mortality, growth, and development in two populations of Rana temporaria that differ in the pH of their breeding ponds. In a population with pH neutral breeding sites, low pH treatment caused a prolongation in embryogenesis and an increased embryonic mortality, a higher proportion of deformed hatchlings and an increased larval time. Embryos and larvae from a population that was exposed naturally to low pond pH were more pH tolerant, as the only effect of low pH was increased larval time.

Here I report on the reproductive characteristics of an insular population of the lacertid lizard Podarcis hispanica, which inhabits the Cíes Islands, an archipelago formed by three small islands off the northwest coast of Spain. The clutch characteristics of the population were investigated on the basis of clutches laid by pregnant females captured on these islands in 1999 and 2000. Other data were obtained principally by mark-recapture experiments. The egg-laying cycle of live females was determined by ventral palpation. Enlarged follicles were detected from March to July, and the laying period extended from April to the second half of July. The larger females initiated reproductive activities early in the season and produced up to three clutches annually, whereas the smaller individuals laid only a single clutch. Reproductive performance was related mainly to female size. Clutch size, individual egg mass, clutch mass, and hatchling size increased with the length of the females. I also examined the extent to which the reproductive characteristics of this insular population of P. hispanica diverged from those in other populations of the same species. I found no pronounced differences between these populations and other mainland populations of the same species of like body size. Several hypotheses may be proposed to explain the lack of major differences in reproductive characteristics (egg size and number). The first has to do with the relatively short length of time that this population has been isolated, and, therefore, it would still be too early for any divergence to have manifested itself. A second hypothesis is that the selection gradient for reproductive traits on the Cíes Islands may have remained similar to that on the mainland. A third hypothesis deals with the limitations imposed by the reduced body volume of this small-sized species on egg growth in conjunction with the shorter laying period of this population in an Atlantic climate.