No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Depth Zonation, Micro habitat, and Morphology of Three Species of Acanthemblemaria (Pisces: Blennioidea) in the Guif of California, Mexico
Abstract
The utilization of the spatial resources of refuge type, size and depth placement is investigated in the three sympatric species of Acanthemblemaria at the cape region of Baja California, Mexico. A. balanorum occupies barnacle testes (Balanus tintinnabulum), A. macrospilus occupies barnacles and mollusk tubes (vermetid gastropods and pholadids), and A. crockeri occupies only mollusk tubes (pholadids). Refuge diameter overlap is higher than overlap in depth. A. crockeri consistently occupies depths below 5m. Competition experiments for barnacle refuges among the three species indicate that A. balanorum is a superior competitor for such refuges. Prior residency of a less superior species changes the outcome of refuge competition in its favor. The morphological specialization of A. balanorum and A. macrospilus is evident in a high correlation between head size and standard length. A. balanorum selects refuges with entrance diameters highly correlated to standard length.
... This is especially true for the intertidal species, for which a tight association with the substratum can prevent the risk of displacement caused by water turbulence (Gibson, 1969;Gonçalves and Almada, 1998). Territoriality is quite common in many species, not only during the breeding season (e.g., Almada et al., 1987Almada et al., , 1992Almada et al., , 1996Almada and Santos, 1995;Gonçalves and Almada, 1998), but also throughout the year, probably to ensure an efficient use of food and shelter resources (Gibson, 1969(Gibson, , 1982Lindquist, 1985;Koppel, 1988;Mayr and Berger, 1992). ...
... Microhabitat partitioning between ecological related reef fish species has been well documented (Stephens et al., 1966(Stephens et al., , 1970Greenfield and Greenfield, 1982;Lindquist, 1985;Mayr and Berger, 1992;Ormond et al., 1996;Davies, 2000;Munday, 2004;Feary and Clements, 2006). Moreover, many fishes either actively select specific microhabitats at settlement (Carr, 1991;Levin, 1991) or emigrate to them during juvenile or adult stages (Lewis, 1997;Faria and Almada, 2001). ...
... Greenfield and Johnson (1990) demonstrated that different habitats, which can be adjacent to each other, presented distinctive blennioid assemblages. The chaenopsids provide many examples of high habitat specificity within the blennioidei (e.g., Greenfield and Greenfield, 1982;Lindquist, 1985;Hastings 1986Hastings , 1988Hastings , 1992Clarke, 1992;Clarke and Tyler, 2003). An example of this very high level of microhabitat specificity is the segregation of the species Emblemariopsis pricei and Emblemaria pandionis. ...
... Clarke (unpubL) has shown that A, spinosa shelters primarily in burrowing bivalve holes, serpulid and vermetid tubes, and clionid sponge cavities. Although small and inconspicuous, Acanthemblemaria species can reach high densities, averaging up to 60'm-2 in some areas (Lindquist, 1985), undoubtedly being the most abundant fishes in some habitats. Consequently, they are particularly suitable for population studies through manipulative experiments. ...
... occupies a depth range of 2 to 6 m whereas A. spinosa was found from 4 to 22 m, and in none of seven transects did these species overlap. MoUes (1978) has shown a vertical separation between two chaenopsids with habits similar to Acanthemblemaria (Protemblemaria bicirris and Emblemaria hypocanthus) on artificial habitats in the Gulf of California. Lindquist (1975 Lindquist ( , 1985) demonstrated clear resource separation based primarily on water depth and secondarily on refuge diameter for three species of Acanthemblemaria also in the Gulf of California and P. Hastings (pers. comm.) has shown experimentally that the depth separation of two of these is maintained by competition. Food may overlap ...
... MoUes (1978) has shown a vertical separation between two chaenopsids with habits similar to Acanthemblemaria (Protemblemaria bicirris and Emblemaria hypocanthus) on artificial habitats in the Gulf of California. Lindquist (1975 Lindquist ( , 1985) demonstrated clear resource separation based primarily on water depth and secondarily on refuge diameter for three species of Acanthemblemaria also in the Gulf of California and P. Hastings (pers. comm.) has shown experimentally that the depth separation of two of these is maintained by competition. ...
Two species of hole-dwelling blenny, Acanthemblemaria spinosa and A. aspera, were studied on a coral reef in St. Croix, U.S. Virgin Islands, during two field periods 6 years apart (1980 and 1986) to determine degree of population stability, habitat saturation, and interspecific competition. A. spinosa increased from 1.18 to 1.78 fish · m−2 and A. aspera increased from 0 to 1.37 fish · m−2 for a combined 2.71-fold increase. Both species were abundant in the 5 to 9 m depth range in 1986 but absent from the 1 to 3 m depth range. Transplantation experiments in 1980 indicate that the shallower unoccupied areas are physically suitable for survival and provide adequate food for A. spinosa to persist in a reproductive state for 7 weeks. A. spinosa occupied the higher portions of dead corals in both periods whereas A. aspera occupied the lower portions in 1986, being virtually absent in 1980. Experiments with transplanted fish on artificial habitats indicate that both species prefer the higher portions but A. spinosa excludes A. aspera when they co-occur. Removal of blennies from their natural holes results in 86% of the A. spinosa holes being reoccupied within 2 days whereas the corresponding percentage for A. aspera is 35. It is tentatively concluded that 1980 was an unusual year due to the passage of two hurricanes near St. Croix in the fall of 1979; storms would disproportionately depress A. aspera because it shelters close to the bottom. It is argued that in the case of spatially-clustered organisms, strong intraspecific competition can occur in an unsaturated environment, but whether or not this also applies to interspecific competition is unclear.
... Interspecific competition in reef systems can be studied in different ways. First, the use of a shared resource such as food (Clarke 1992; Robertson 1996; Nieder 1997), habitat (Munday et al. 2001), or shelter (Larson 1980; Lindquist 1985) can be measured. Additionally, interspecific dominance T. J. Rauch Department of Biological Sciences, University of Southern Mississippi, 5018, Hattiesburg MS 39406-5018, USA Present Address: T. J. Rauch (&) Department of Biological Sciences, William Carey University, 498 Tuscan Ave, WCC 203, Hattiesburg, MS 39401, USA e-mail: trauch@wmcarey.edu ...
... Additionally, interspecific dominance T. J. Rauch Department of Biological Sciences, University of Southern Mississippi, 5018, Hattiesburg MS 39406-5018, USA Present Address: T. J. Rauch (&) Department of Biological Sciences, William Carey University, 498 Tuscan Ave, WCC 203, Hattiesburg, MS 39401, USA e-mail: trauch@wmcarey.edu can be measured using lab (Koppel 1988; Mayr and Berger 1992; Munday et al. 2001) and field (Lindquist 1985) manipulations. Results take the form of simple dominance for a resource or the effects of prior residence and past experience, which may change simple dominance relationships (Grossman 1980; Mayr and Berger 1992). ...
Interspecific interactions can determine the abundance and distributions of animals. Seaweed blennies, Parablennius marmoreus, and tesselated blennies, Hypsoblennius invemar, are found in barnacle cavities on offshore petroleum platforms in the northern Gulf of Mexico. I measured the interspecific
resource defense interactions between these fishes in aquaria. Seaweed blennies were dominant over tesselated blennies when
equal-sized fishes were tested. No difference in dominance was found when tesselated blennies had a 10% advantage in size.
However, tesselated blennies were able to successfully defend cavities against equal-sized competitors when given the advantage
of prior residence. This prior residence advantage persisted despite seaweed blennies having the advantage of past experience.
Seaweed blennies attain a larger size on petroleum platforms, but empty barnacle cavities are common in this environment.
Tesselated blennies are able to colonize and successfully spawn because they can enter an empty barnacle cavity, gain the
advantage of prior residence, and successfully defend this cavity.
... Interestingly, the occupants may also be sheltered from oil pollution and emulsifier cleansing (Nelson-Smith, 1968). The barnacle test is such an important resource for the chaenosid blennies of the genus Acanthemblemaria that competition is intense between its three congeners (Lindquist, 1985). The blenny Hypsoblennius brevipinnis (Günther, 1861) is absent where large barnacle tests are not available (Gilligan, 1980). ...
The barnacles Tetraclita singaporensis and T. squamosa have a thick test to protect the animals against the diverse environmental stress of the tropical intertidal zone and also against predation by muricid gastropods. After the death of the barnacle, however, the empty test is often taken over by other marine fauna as well as semi-terrestrial animals. The sphaeromatid isopod Dynamenella ptychura was the most abundant inhabitant in empty tests observed in Singapore and Malaysia. Ovigerous crustaceans were common. Gastropod specimens comprised almost entirely juveniles of common intertidal species, including those of the littorinids Littoraria articulata and L. strigata . Gastropod eggs and veligers, insect larvae, pupae and nymphs, and spider spiderlings and immatures were also present. The haminoeid gastropod Smaragdinella was the dominant animal colonizing barnacles in a succession experiment. Temperature was significantly lower inside the empty test than outside, by 0.2°C. Almost 40% of the barnacle tests remained attached to the substratum for more than four months after the death of the individuals.
... Its demersal eggs are laid deep inside the male's shelter hole, which are guarded by the male until they hatch into planktonic larvae (Clarke and Tyler 2003). The availability of such holes is a limiting resource for blenny abundance and, therefore, larger blennies dominate smaller ones for access to such holes as long as they can fit inside, which is relevant in both intraspecific and interspecific competition for space (Greenfield and Greenfield 1982;Lindquist 1985;Buchheim and Hixon 1992;Patzner 1999;Wilson et al. 2013). ...
The distribution, abundance, and habitat preferences of the spinyhead blenny, Acanthemblemaria spinosa (Perciformes, Blennioidei, Chaenopsidae), were studied on coral reefs along the leeward side of Curaçao, southern Caribbean. The blennies inhabited small holes inside coral, which predominantly consisted of calcareous tubes constructed by coral-associated serpulid worms of the species Spirobranchus giganteus. About 50 % of the fish inhabited holes in dead coral, and the rest had their holes in live corals of eight species. The fishes showed a clustered distribution pattern and their abundance was higher at shallow depths (5 and 10 m) than at 15 m. Although males generally had a larger body size than females and needed larger holes for shelter and guarding eggs, no sexual dominance in hole selection was found. The position of the holes varied in elevation height above the reef floor, which showed a positive correlation with fish size.
... Acanthemblemaria hastingsi is limited to the GOC where it is known to occur from Mulegé to Cabo San Lucas along the Baja Peninsula and between Isla San Pedro Nolasco and Isla San Ignacio de Farallon along the Mexican continental mainland (Hastings & Robertson 1998). Gulf species in this genus are known to exhibit depth partitioning, and A. hastingsi is typically found 0-13 m deep (Lindquist 1985). ...
Molecular analysis of the chaenopsid tube blenny, Acanthemblemaria macrospilus Brock, reveals species-level differentiation and the existence of a new species, described here as Acanthemblemaria hastingsi, using molecular and morphological data. This new species is a member of the hancocki species group and is limited to the Gulf of California. It is distinguishable from A. macrospilus by mitochondrial gene sequences of cytochrome C oxidase I and D-loop region as well as by coloration. This differentiation is also supported to a lesser extent by the nuclear ribosomal protein S7 first intron. There is no geographic overlap in the ranges of these species, as they occur exclusively on either side of the Sinaloan Gap.
... However, most studies have been concerned with coral reef (Clarke 1977, Luckhurst & Luckhurst 1978, Bouchon-Navaro 1986, Greenfield & Johnson 1990, Pitts 1991) and freshwater (Werner et al. 1977, Grossman & Freeman 1987, Grossman et al. 1987a, b, Greenberg 1991, Copp 1992 ) communities. Investigations have demonstrated the importance of substratum type (Luckhurst & Luckhurst 1978), depth (Lindquist 1985, Illich & Kotrschal 1990), and algal abundances (Carr 1989) in particular, in the structuring of fish communities. ...
An assemblage of Gobiidae in Lough Hyne, southwest Ireland, was investigated to assess interspecific and seasonal differences in microhabitat utilisation. Five microhabitat guilds were distinguished using canonical correspondence analysis, comprising 2 semi-hyperbenthic guilds and 3 epibenthic guilds. Differential preferences for each environmental variable measured were examined using Jacobs' version of Ivlev's electivity index. Members of different guilds exhibited differential microhabitat use, whilst members of the Same guild exhibited only subtle differences in microhabitat utilisation. Few seasonal variations were observed, with guilds maintaining their separation seasonally.
... Most have a sedentary attitude related with a cryptic behaviour adopted to reduce predation risk and to increase efficiency in capturing prey. To further reduce predation and impact of unfavourable environmental conditions (Shulman 1984, Koppel 1988, Forsgren and Magnhagen 1993, gobies use holes or crevices proportional to body size (Lindquist 1985;Koppel 1988;Hixon and Beets 1989) as refuge off the breeding season and as nest during spawning. Gobies are highly territorial defending vigorously nests and shelters from conspecific intruders during the whole year, using both visual and acoustic signals. ...
We present a detailed description of the territorial behaviour of G. cruentatus. We staged simulated intrusions in a captive setting to overcome the inherent difficulty of observing these interactions in the field. An 'intruder' was introduced in an experimental arena containing a 'resident' male. The response of the resident was video-taped and audio- recorded. The tested animals (two groups of 5 animals each) played in turn both the resident and the intruder roles. A total of 40 territorial interactions were recorded. Twenty-six behavioural units (BU) were identified and described according to their physical and functional interpretations; average duration and frequency of occurrence of each BU were reported. During the contests, resident fish mainly produced sounds. According to the 'bourgeois strategy', contests were settled in a maximum of 10 min, with the owner of the territory usually resulting the winner. Differences in body size seemed not to influence the contest outcome, whereas resource value did.
... Small benthic fish are nesting in holes and crevices in order to protect themselves and the fertilized eggs from predators (LindqUiST, 1985). holes, which have narrower entrances than crevices, enable the territorial male to prevent entry of other males, and thus to defend its hole. ...
The present research aimed at evaluating the importance of endolithic holes for the spawning of blennies and at studying the selection and utilization of holes by blennies in the Gulf of Trieste. The study was conducted using the all-occurrence sampling method, a non-destructive visual census method, aided by SCUBA. Resident, egg-guarding males of Lipophrys dalmatinus, Lipophrys canevae, Aidablennius sphynx, Parablennius incognitus, Parablennius zvonimiri and Parablennius rouxi were caught. Species-specific differences in the utilization of holes were found for species that nest in endolithic holes. Smaller species (e.g. Lipophrys dalmatinus and Lipophrys canevae) choose holes that are little larger than their heads and approximately as long as their body, which prevent small males from being dislodged by big-ger ones. Bigger species that are probably less exposed to interspecific competition for holes, choose mostly holes with an entrance diameter twice as big as their head diameter and much longer than their body. Species living in shallow waters (e.g. Aidablennius sphynx) prefer hole positions exposed to day-light, while species living in deeper waters were mostly found in the shade of boulders and rocks.
... Chaenopsid blennies of the genus Acanthemblemaria constitute 18 species (Almany and Baldwin, 1996) and are among the most inconspicuous diurnal fishes on coral reefs. They can be very abundant, reaching densities as high as 60 m −2 (Lindquist, 1985) and 200 m −2 (J. Buchheim, pers. ...
In order to determine the extent to which tube blennies depend on food derived from within or outside of the reef system, the diets of Acanthemblemaria spinosa, A. aspera, A. greenfieldi and A. paula were compared with food availability using plankton, benthic and gut sampling. All species fed primarily on copepods, but A. spinosa consumed calanoids and cyclopoids of planktonic origin whereas the other species consumed harpacticoids of benthic origin. This pattern correlates with the occurrence of A. spinosa in tall corals whereas the other species are found in corals close to the reef surface. Calanoids were more abundant 1 m above the reef surface than <0.5 m above the reef surface. Oxygen consumption rates were determined for the above species and Emblemariopsis pricei and E. ruetzleri. On the oxygen consumption versus body weight graph, A. spinosa shares a high slope with the Emblemariopsis species, which was three times greater than the slopes of other species of Acanthemblemaria. It is not known if the high metabolic rate of A. spinosa is a consequence of the greater food availability in its microhabitat, an adaptation for acquiring the higher quality microhabitat, or both. In any case, A. spinosa is the only Acanthemblemaria species in this study that imports nutrients to the reef by consuming plankton.
... Most have a sedentary attitude related with a cryptic behaviour adopted to reduce predation risk and to increase efficiency in capturing prey. To further reduce predation and impact of unfavourable environmental conditions (Shulman 1984, Koppel 1988, Forsgren and Magnhagen 1993), gobies use holes or crevices proportional to body size (Lindquist 1985; Koppel 1988; Hixon and Beets 1989) as refuge off the breeding season and as nest during spawning. Gobies are highly territorial defending vigorously nests and shelters from conspecific intruders during the whole year, using both visual and acoustic signals. ...
We present a detailed description of the territorial behaviour of G. cruentatus. We staged simulated intrusions in a captive setting to overcome the inherent difficulty of observing these interactions in the field. An 'intruder' was introduced in an experimental arena containing a 'resident' male. The response of the resident was video-taped and audio-recorded. The tested animals (two groups of 5 animals each) played in turn both the resident and the intruder roles. A total of 40 territorial interactions were recorded. Twenty-six behavioural units (BU) were identified and described according to their physical and functional interpretations; average duration and frequency of occurrence of each BU were reported. During the contests, resident fish mainly produced sounds. According to the 'bourgeois strategy', contests were settled in a maximum of 10 min, with the owner of the territory usually resulting the winner. Differences in body size seemed not to influence the contest outcome, whereas resource value did.
... In addition, the males using the size-mismatched large nests will need to defend their nests against relatively larger egg predators. Moreover, the mismatched loose entrance may increase the risk of predation not only on eggs but also on egg-tending males themselves (Crabtree & Middaugh, 1982;Lindquist, 1985). Another possibility for the male preference for tight nests is to exclude sneaker males. ...
Field and laboratory studies were conducted to clarify the processes contributing to the size-assortative nest use by males of a paternal brooding blenny Rhabdoblennius ellipes. The use of natural and artificial nests by males in the field was highly size-assortative; males used smaller nests even when larger nests were available. Aquarium nest choice experiments without a competitive male strongly suggested that the size-assortative nest use by males is not the result of male–male competition for larger nests, but male preference for size-matched nests. Males were likely to choose nests on the basis of the nest entrance size rather than nest length and volume, suggesting that the size-assortative nest preference in this species is an adaptation to predation pressure against eggs and resident males.
... Consequently, they are very different from the pomacentrids so often used in population and community studies of coral reef fishes. Fishes of this genus live in small holes in hard substrate (Lindquist 1985) where they spend most of their active time visually scanning the surrounding water and substrate for small invertebrates which serve as their food (Greenfield and Greenfield 1982; Lindquist and Kotrschal 1987). On spotting a prey item, a blenny will dart from its shelter, grasp the prey, and rapidly reenter its shelter tail first. ...
Spinyhead blennies (Acanthemblemaria spinosa) and roughhead blennies (A. aspera) are planktivorous hole-dwelling fishes that live in dead coral skeletons. Both species are known to choose shelters high above the reef surface (although spinyheads displace roughheads downwards). To test the hypothesis that this preference is due to greater plankton availability in higher locations, fish were placed on artificial habitats located 15 cm and 100 cm above the surface of a natural reef. Both species experienced higher feeding rates, growth rates, and fecundities in high locations, and spinyhead rates generally exceeded roughhead rates at a given height. Under laboratory conditions, oxygen consumption by spinyheads was 1.6 times greater than that of roughheads and this corresponds well with the 1.8 ratio of feeding rates under controlled aquarium conditions. This information provides a partial explanation for the observed microhabitat distribution and resulting coexistence of these competing species: it is hypothesized that spinyheads have an advantage in agonistic interactions because of their higher metabolic rates, thus excluding roughheads from high sites, but that roughheads can persist at low sites because their lower metabolic rates result in lower food demands. A model is presented that predicts varying occurrences and vertical distributions of these species in locations with different zooplankton densities.
... Members of the genus Acanthemblemaria are among the most closely tied to the substrate, to the point of being called hemisessile (Kotrschal and Lindquist 1986). They reach densities of 5 fish m -2 over large reef areas (Clarke 1996) and can achieve local densities as high as 60 fish m -2 (Lindquist 1985). Thus, these fishes may be overlooked contributors to nutrient input on coral reefs. ...
The chaenopsid blenny Acanthemblemaria spinosa occupies topographically high locations on coral reefs where flow speeds and turbulence are frequently greater than those
experienced by its congener, A. aspera, which occupies locations close to the reef surface. To investigate the adaptive mechanisms resulting in this microhabitat
differentiation, the foraging effort and success of these fishes were determined in laboratory flumes that produced flow conditions
approximating those experienced in the field. Individual fish were subjected to unidirectional (smooth and turbulent) and
oscillatory flows while they fed on calanoid copepods, Acartia tonsa, whose vulnerability to predation varies with water flow. In unidirectional flow both blenny species had their greatest foraging
success at intermediate flow speeds (ca. 10cms−1) and under turbulent flow. Under all conditions, Acanthemblemaria spinosa exhibited greater foraging effort and attacked at greater distances, greater mean water speeds, and in oscillatory flow,
over a greater proportion of the wave cycle than did A. aspera. A. spinosa also exhibited greater foraging success under turbulent flow conditions. These differences in feeding patterns allow A. spinosa, with its higher metabolic rate, to occupy the more energetic higher locations in corals where planktonic food is more abundant.
A. aspera occupies the poorer quality habitat in terms of planktonic food availability but its lower metabolic rate allows it to thrive
there. Consequently, these species divide the resource in short supply, i.e., shelter holes, based on their differing abilities
to capture prey in energetic water conditions in conjunction with their differing food energy requirements.
... Focal blennies showed no obvious reaction to the observer who maintained a distance of at least 1.5 m from subjects. Prior to focal observation intervals, individuals were scored as resident (in a shelter; Fig. 1 (Stephens 1963;Lindquist 1985;Lin et al. 2009); the anterior portion of the body bearing blotches in females was visible on all focal individuals included in this study. Most individuals \20 mm SL typically do not express sex-specific coloration, so all ''small'' individuals were classified as ''juveniles.'' ...
Ecological specialization is common on coral reefs and almost certainly contributes to the high diversity of fishes and invertebrates
associated with reefs. Here, the recruitment pathway of an endemic Gulf of California fish, the Browncheek Blenny, Acanthemblemaria crockeri (Teleostei: Chaenopsidae), which specializes as an adult on vacant invertebrate tests or tubes, is reported. Like most reef
fishes, Browncheek Blennies have a planktonic larval stage that leaves the reef and later settles on suitable habitat as a
fully developed juvenile. These blennies follow a clear, “two-step” recruitment pathway, however, and do not reside in invertebrate
tests until reaching an adult body size. Individual juveniles and adults were observed for 3min intervals in order to develop
average time budgets for this species. Members of both sexes and all post-settlement life-history stages were included in
the analysis. The difference in habitat use by post-settlement juveniles and adults is striking; the average juvenile spends
none of its time inside a test, and the average large adult spends all of its time inside a test. Using data on intermediate-sized
individuals, the behavioral change associated with invading a test was determined to be size-cued, and it occurs between 20
and 30mm standard length. Changes in feeding and predator avoidance behaviors are also associated with the ontogenetic shift
from life in the open to life in a shelter. Addition of artificial shelters demonstrated the essential role of access to this
specialized resource in the population regulation of adults but not juveniles of these blennies.
... Chaenopsins are significant models for the study of ecology and evolution, in part because they are site attached, often abundant (Thomson and Gilligan, 2002) and readily observed. As a consequence, the ecology, habitat use and mating behavior of several species are relatively well known (e.g., Clarke, 1999;Hastings, 1986Hastings, , 1988aHastings, ,b, 1992aHastings, , 2001aHastings, , 2002Hastings and Galland, 2010;Lindquist, 1980Lindquist, , 1985. Tube blennies occupy shelters in a variety of ecological settings that include rocky reefs, coral reefs, and along the margins of these reefs where sand and shell rubble are common (see Table 1). ...
Phylogenetic relationships within tube blennies (Chaenopsinae) were reconstructed using Bayesian, maximum parsimony and likelihood analyses of multiple molecular markers (mitochondrial DNA: COI; nuclear DNA: TMO-4C4, RAG1, Rhodopsin, and Histone H3) and 148 morphological characters. This total-evidence based topology is well-resolved and congruent across analytical methods with strong support for the monophyly of the Chaenopsinae, all included genera and several internal nodes. A rapid radiation in the early evolution of chaenopsins is inferred from the relatively poor support values for relationships among basal lineages and their divergence into different habitats (rocky reefs, coral reefs and the reef/sand interface). Rates of molecular evolution in chaenopsins, as inferred by divergence among four putative transisthmian geminate species pairs, are rapid compared to other fishes. Conflicts among genetic markers and morphology are especially evident within the genus Coralliozetus, with different species relationships supported by morphology, TMO-4C4, and RAG1 plus Rhodopsin. This study hypothesizes a novel sistergroup relationship between Ekemblemaria and Hemiemblemaria, consistent with morphological, molecular and habitat use data. Our total evidence phylogenetic hypothesis indicates that previously hypothesized morphological characters supporting a close relationship between Hemiemblemaria and Chaenopsis plus Lucayablennius resulted from convergent evolution in these relatively free-swimming blennies.
... Small benthic fish are nesting in holes and crevices in order to protect themselves and the fertilized eggs from predators (LindqUiST, 1985). holes, which have narrower entrances than crevices, enable the territorial male to prevent entry of other males, and thus to defend its hole. ...
The present research aimed at evaluating the importance of endolithic holes for the spawning of blennies and at studying the selection and utilization of holes by blennies in the Gulf of Trieste. The study was conducted using the all-occurrence sampling method, a non-destructive visual census method, aided by SCUBA. Resident, egg-guarding males of Lipophrys dalmatinus, Lipophrys canevae, Aidablennius sphynx, Parablennius incognitus, Parablennius zvonimiri and Parablennius rouxi were caught. Speciesspecific differences in the utilization of holes were found for species that nest in endolithic holes. Smaller species (e.g. Lipophrys dalmatinus and Lipophrys canevae) choose holes that are little larger than their heads and approximately as long as their body, which prevent small males from being dislodged by bigger ones. Bigger species that are probably less exposed to interspecific competition for holes, choose mostly holes with an entrance diameter twice as big as their head diameter and much longer than their body. Species living in shallow waters (e.g. Aidablennius sphynx) prefer hole positions exposed to daylight, while species living in deeper waters were mostly found in the shade of boulders and rocks.
The utilization of the spatial resources of two syntopic blenniid species - Blennius cunevue and Blennius incognitas - has been investigated in silu and under laboratory conditions. Both species occupy bore holes of the mussel Lithophugu in the sublittoral zone. B. cunevue dominates the more shallow zone (x̄= 0.68 m) and prefers smaller (x̄= 12.76 mm diameter) and horizontal bore holes. B. incognitus inhabits the same depth range as B. cunevue but occupies larger bore holes (x̄= 14.57 mm) in a deeper zone (x̄= 0.86 m). Individuals of B. incognitus do not prefer a special inclination angle. The two blenniid species defend territories with different intraspecific sizes: the mean territory radius of B. cunevue is 6.87 mm, of B. incognitusx̄= 10.95. Mechanisms to reduce competition include different activity rhythm, interspecific social dominance, and differences in territoriality. B. cunevue is the dominant species; its territories arc defended against conspecifics and against B. incognitus.
The utilization of empty holes of endolithic bivalves (Gttsirocluwnu dubui by Bknnius chdmcitinus, and Litliophaga lithophaga by all other species) as shelters by egg-guarding males of nine species of Adriatic Blenniidae is compared. A wide spectrum of entrance sizes to these “standardized” shelters is used with the most frequent utilization ranging between 1(H) and 275 mm: (11.2–18.8mm mean entrance diameters). As a trend within and between species, larger fish utilize holes with disproportionately wider entrances. There arc significant differences between species in the means of “fit” of the heads within the entrances: the heads of B. dulmaibuts, B. canaeve, B. adrialicus, and B. zvonimiri“fit” tightly into their entrances whereas the two large species, B.puvo and B. tentacularis, which only facultatively use holes of boring mussels for breeding, arc found in holes with “oversized” entrances. In most species mean shelter depth approximates mean body length. Species which tightly “fit” their entrances tend to stay longer when disturbed mechanically or chemically compared to those with only a loose “fit”. The ecological and evolutionary significance of these patterns is discussed.
Tube blennies (Chaenopsidae) have the largest relative mouth size compared with other blennioids. Their peculiar oral jaw apparatus may be interpreted as adaptation towards opportunistic feeding, making a wide spectrum of prey types and sizes accessible for these “hemisessile” fishes.
Three sympatric species of Gulf of California Acanthemblemaria show different, though overlapping habitat and microhabitat utilization, but are nearly identical in feeding. Accordingly, sizes and shapes of the oral jaw apparati are very similar in the species under consideration. Possible reasons for this apparent lack of ecomorphological divergence are discussed.
Gut contents of a total of 180 specimens of the blennies Scartella cristata (L., 1758). Parablennius pilicornis (Cuvier, 1829) and Lipophrys trigloides (Valenciennes, 1836) caught in the course of 1990 off Playa de la Mora (Prov. Tarragona, Spain) were analysed. The quantitative composition of food differed considerably between the 3 species (mostly algae in the herbivorous S. cristara. Amphipoda in the carnivorous L. trigloides and a variety of items in omnivorous P. pilicornis). The 3 species in the course of a year overlap little in food resource use, with overlap reaching its maximum in April when juvenile Mytilus on the rock substrate are in ample supply. In S. cristata and L. trigloides, diversity of food items is similarly lowest in July and April, respectively, when these 2 species attain their optimal nutritional status. In contrast, diet diversity and food intake are inversely correlated in P. pilicornis. Evidently, resource sharing between blenniid species in the rocky shore habitat is clearly structured, but subject to seasonal dynamics. It is concluded that food niche analyses should consider seasonal plasticity in feeding patterns and refrain from premature conclusions based on short-term studies.
This paper presents a comparative analysis of territoriality in three intertidal (Lipophrys pholis, Coryphoblennius galerita,
Salaria pavo) and two subtidal (Tripterygion delaisi, Parablennius pilicornis) blennioid fishes. Focal-animal observations
of males guarding eggs showed that: (i) intertidal species had smaller territories that were less frequently patrolled; (ii)
in subtidal species feeding was limited to the territory, while in intertidal fishes a substantial proportion of the feeding
acts occurred outside the defended area; (iii) intertidal species spent less time out of the nest and showed a lower level
of locomotory activity; (iv) subtidal species were subjected to a higher number of territorial intrusions with more species
intruding their territory, some of them potential egg predators; (v) subtidal species performed several water column displays
that played a significant role in courtship, while in intertidal fishes these displays are almost absent. Signalling without
the presence of a female was almost absent in intertidal species. It is argued that intertidal fishes minimize the time spent
out of the nest and the loss of contact with the substrate, features that may be of high survival value in conditions of strong
turbulence. Although intertidal species have a reduced time available for feeding, this may be compensated by lower levels
of locomotory activity, territorial defense and risk of egg predation.
Neotropical reef fish communities are species-poor compared to those of the Indo-West Pacific. An exception to that pattern is the blenny clade Chaenopsidae, one of only three rocky and coral reef fish families largely endemic to the Neotropics. Within the chaenopsids, the genus Acanthemblemaria is the most species-rich and is characterized by elaborate spinous processes on the skull. Here we construct a species tree using five nuclear markers and compare the results to those from Bayesian and parsimony phylogenetic analyses of 60 morphological characters. The sequence-based species tree conflicted with the morphological phylogenies for Acanthemblemaria, primarily due to the convergence of a suite of characters describing the distribution of spines on the head. However, we were able to resolve some of these conflicts by performing phylogenetic analyses on suites of characters not associated with head spines. By using the species tree as a guide, we used a quantitative method to identify suites of correlated morphological characters that, together, produce the distinctive skull phenotypes found in these fishes. A time calibrated phylogeny with nearly complete taxon sampling provided divergence time estimates that recovered a mid-Miocene origin for the genus, with a temporally and geographically complex pattern of speciation both before and after the closure of the Isthmus of Panama. Some sister taxa are broadly sympatric, but many occur in allopatry. The ability to infer the geography of speciation in Acanthemblemaria is complicated by extinctions, incomplete knowledge of their present geographic ranges and by wide-spread taxa that likely represent cryptic species complexes.
Peptic ulcer bleeding is a serious medical problem with significant morbidity and mortality. Endoscopic therapy significantly reduces further bleeding, surgery and mortality in patients with bleeding peptic ulcers and is now recommended as the first hemostatic modality for these patients. The efficacy of large-dose proton pump inhibitor (PPI) therapy in reducing re-bleeding after endoscopic therapy has been supported by evidence derived from randomized controlled trials. It may be premature to recommend small-dose intravenous injection PPI after endoscopic hemostasis in patients with bleeding ulcers. An updated systematic review shows that PPI therapy before endoscopy significantly reduces the proportion with major stigmata and requirement for endoscopic therapy at index endoscopy. Some studies show that there is no significant difference between oral and intravenous PPIs in raising intragastric pH. However, clinical data is lacking in patients with peptic ulcer bleeding to date.
The Gulf of California endemic reef fish, Acanthemblemaria crockeri (Blennioidei, Chaenopsidae), reportedly has two colour morphs, one with melanic lateral spots ('Gulf' morph) and one with orange spots ('Cape' morph). In this study, we recorded colour morph in both males and females and collected mitochondrial DNA sequence data for cytochrome c oxidase I (COI) and tRNA-Pro/D-loop of specimens from throughout the Gulf to explore the genetic basis of the colour morphs. Two highly divergent (HKY + I distance = 11.9% for COI), reciprocally monophyletic lineages were identified, consistent with the presence of two parapatric species. A 30-km gap between the distributions of mitochondrial lineages roughly corresponds to a hypothesized former seaway across the Baja California peninsula north of La Paz, although the estimated divergence time (1.84 million years ago) is more recent than the hypothetical seaway (3-4 million years ago). Surprisingly, the distribution of mitochondrial species is not congruent with the distribution of either male or female colour morphs. Our analysis also revealed significant population differentiation within both species and no shared haplotypes among populations. The northern Gulf species includes four populations (NB, CB, NM and CM) corresponding to northern and central Baja and northern and central mainland sites, while the Cape species includes two populations (SB and SM) corresponding to the Baja and mainland sides of the southern Gulf. The NB/CB division corresponds to a hypothesized Plio-Pleistocene mid-peninsular seaway. The level of genetic divergence documented in this lineage is extraordinary for a marine fish with a pelagic larval stage within a semi-enclosed basin.
The relationships of the red and melanic color phases of the browncheek blenny, Acanthemblemaria crockeri, are examined. Pure populations of the red phase occur near the heads of the San Lucas and Los Frailes submarine canyons. Introgressive populations of the two phases occur together in a zone of sympatry from Los Frailes to at least Guaymas (central Gulf of California), where the red phase is limited almost completely to females that vary from pure red to intermediate (combination of the red and melanic phases). These red and intermediate females are both less abundant and decreasingly red as one goes north in the zone of sympatry. All males in the zone of sympatry are of the melanic phase and the proportion of melanic phase females increases abruptly in central gulf populations. The distribution pattern suggests: 1) the pure red phase populations of the cape region of Baja California probably developed as an insular population where red can be adaptive in these deeper submarine canyon populations; 2) these pure red phase populations may be homozygous for the red allele; 3) red phase males are not fit north of the cape region either because nonmelanic males cannot attract females (melanic color is important in sexual displays) or because red is obvious and red individuals are removed by predators or a combination of both; and 4) the intermediate phase females are maintained in central gulf populations because of selection for increased sexual dichromatism. Unfortunately, these suggestions do not, at present, adequately explain the odd sex-related distribution of individuals in the zone of sympatry.
A new member of the "hancocki" species complex, Acanthemblemaria castroi, is described from the Galapagos Islands. A new species, Coralliozetus springeri, is described from the Pacific coast of Panama, forming a geminate pair with C. cardonae from the Caribbean Sea. The description of the latter species is supplemented as is that of Chaenopsis schmitti Böhlke. The ranges of three species are extended: Coralliozetus boehlkei Stephens to Cocos Island, Coralliozetus angelica (Böhlke and Mead) to Socorro Island, the Revillagigedos, and Acanthemblemaria balanorum Brock to Bahia Piñas, Panama. Meristic variation with latitude, size reduction in the Cocos Island population, and reproductive behavior are described for Acanthemblemaria macrospilus Brock.
Three species of the blenniid genus Hypsoblennius, H. gilberti, jenkinsi, and gentilis, coexist in the shallow waters of the San Diegan Warm Temperate Region. Extensive field and laboratory studies were carried out to determine the degree of ecological differentiation present in these species. The dominant species, H. gilberti and H. jenkinsi show both behavioral and ecological specializations which are lacking in H. gentilis. These differences include: Habitat preference; H. gilberti inhabits the rocky intertidal and adjacent subtidal cobble; H. jenkinsi is found only subtidally, inhabiting boring clam burrows, Serpulorbis tubes or mussel beds. Adult motility: H. gilberti is a meandering species commonly including a radius as large as 15 m within its home range. Individuals return to @'home@' pools at low tide and homing has been demonstrated for displacements as great at 45 m. H. jenkinsi is sedentary rarely wandering more than a meter from its home refuge. Homing was not demonstrated in this species, even for displacements as small as 5 m. Territoriality: Degree of territoriality correlates with movement, the sedentary species is highly territorial while this phenomena is less easily demonstrated in the meandering form. The above differences have been experimentally verified in the laboratory. All species are omnivorous, differences in gut content seem to represent different habitat associations. Reproduction occurs from spring through late summer; the eggs are guarded by the male. Hatching occurs in 4-18 days depending on temperature; the larvae are pelagic for about three months. Adult size differences reflect differing larval and first year growth plus differing longevity; determinate growth has not been demonstrated. Adult size varies between the species and is an important ecological factor. In the small tubiculous species H. jenkinsi, tube size controls fish size (habitat matching) probably through predator selection. Habitats made up of different tube sizes support populations of significantly different mean fish size. In Newport Bay, population structures are altered by a viral infection, Lymphocystis which reaches epidemic levels during the warm months. The ecological differences between the three species seem to indicate that H. gentilis is the most generalized (primitive) form. The specializations of its congeners adapt them to coexistence with limited competition. H. gentilis unspecialized and unable to compete in Southern California survives here in marginal habitats, particularly areas recently modified by man.
The tiny island of South Bimini contains 4 species of lizards of he genus Anolis, a number surpassed only on the 4 largest islands of the Greater Antilles and on 2 very large and nearby satellite islands. These species are syntopic with respect to a two-dimensional area of the ground but divide the habitat according to perch height and perch diameter: sagrei is partly terrestrial but occurs more often on small and large low perches; distichus prefers the trunks and large branches of medium to large trees; angusticipes inhabits small twigs, especially at great heights; and carolinensis is found mostly on leaves or on the adjacent twigs and brances. The size classes of the species are staggered in such a way that the interspecific classes which overlap most in habitat overlap least in prey size. Similarities in prey size and prey taxa for classes of the same species are somewhat greater than those expected on the basis of habitat and morphology alone. The distribution of the species among the vegetation communities of Bimini can be explained on the basis of perch height and diameter preference. Within the same species, the larger lizards usually eat larger food, fewer items, and in sagrei more fruit; and they have a greater average range of food size per digestive tract. One species (distichus) is extremely myrmecophagous: about 75-90% of its food items are ants. In 3 of the 4 species, subadult males take more food and average smaller prey then females of the same head length. That species (distichus) which takes the smallest food items and whose classes overlap the most in habitat preference with those of other species is least dimorphic is size between the sexes. It is suggested that such small, nondimorphic species are best suited for insinuation into complex faunas, whereas larger, dimorphic forms are best for the colonization of empty areas. The usefulness of various measures of "overlap" and "specialization" is evaluated for this lizard association.
The length, breadth, and in part the height, of individual Balanus balanoides and B. crenatus have been measured over several seasons, and the mean specific growth-rates calculated. The B. balanoides had settled at various known intertidal levels, and both species under conditions of permanent submersion.
Under all conditions, except on the highest intertidal panels, length increases rapidly subsequent to settlement and during the early summer. B. crenatus can reach its virtual maximum size (20–25 nun. rostro-carinal length) in a single growing season, under the conditions studied. Late-settled B. crenatus continue to grow further into the autumn, and begin to grow again early in the spring of the second season at the end of which the virtual maximum size is reached. The seasonal growth of both intertidal and submerged B. balanoides is similar, but the growth-rate is a function of submersion, which is, of course, dependent upon the tidal level. However, maximum growth is not reached in the first season and there is consequently relatively more growth in the second season than in B. crenatus .
The mean specific growth-rates in both species decrease with increasing size and, with permanently submerged B. crenatus , there is no suggestion that during the first spring and early summer any change in the environmental factors was effective. On the intertidal panels, the mean specific growth-rates at a given size vary with the tidal level, and this effect is most marked in the smaller barnacles.
The muscle and skeleton anatomy of the pectoral, pelvic, and anal fins are described in 3 Salariin Blenniidae: Salarias fasciatus (sublittoral), Istiblennius edentulus (eulittoral), Alticus kirkii (supralittoral). In A. kirkii these organs are adapted to a climbing habit on the steep rocks beyond the water. The results are compared with those found in Periophthalmus.
The external morphology of 5 species of salariin Blenniidae has been examined. Differences have been established between Salarias fasciatus living in the sublittoral, Antennablennius hypenetes, Istiblennius edentulus and I. flaviumbrinus inhabiting the eulittoral zone, and, especially, Alticus kirkii living on steep rocks of the supralittoral zone. The rays of the anal and (partly) pectoral fins terminate in little hooks; these are most pronounced in A. kirkii and least developed in S. jasciatus. The pelvic fins are short and broad in A. kirkii, but long and slender in the other 4 species. These structures make it possible to cling to uneven substrates. Fins are protected from rough rocks by a well developed cuticula; this is thickest in A. kirkii. Respiratory organs, adapted to function on land, have been discovered in the form of cutaneous blood vessels on the heads and the bodies of A. kirkii, and (less numerous and less developed) in I. edentulus and I. flaviumbrinus. Sensory organs have become specialized in A. kirkii; the eyes protude from the head, and the lateral line is reduced to a small relict. S. fasciatus and A. kirkii must be regarded as terminal representatives of a sequence of development which followed a trend toward the amphibian way of life.
The morphology of the eyes of 3 salariin Blenniidae have been investigated and compared: Salarias fasciatus (inhabiting the sublittoral), Istiblennius edentulus (eulittoral), and Alticus kirkii (supralittoral). An effective protection against desiccation in A. kirkii is offered by the very thick cornea conjunctiva. Extension of the visual field in this species is achieved by protrusion of the eyes from the head, by recession of the dermal pigment, and by a relatively large lense which allows better perception of marginal rays. The retina of I. edentulus is adapted for amphibious vision by the existence of many prominent swellings and folds, and of a central depression into which the lens can be with-drawn. Thereby, the stronger rays of light retraction present on land are focussed on the swellings, since the retina of the depression is under-developed. The cornea conjunctiva and propria of A. kirkii are separated, and thereby constitute an additional eye chamber. Presumably this cavity possesses a lower refractive index than the cornea or water, and thereby enables sharp vision in air, since the light-concentrating effect of the curved cornea is thus diminished. Additionally, the shape of the cornea propria can be varied, since it is centrally connected with the lens; by this means the eye chamber can be extended, enabling displacement of the tocal point of the light rays to correspond with the momentary residence. The adaptations described here for I. edentulus and for A. kirkii have so far not been reported in other amphibious vertebrates.
Twelve species of the fish genusBlennius (Blennioidei, Perciformes) have been investigated with regard to their ecological requirements at 20 distinct localities of the western and southern Mediterranean Sea. The species examined respond differently to the environmental factors temperature, light, salinity, and wave-action.Blennius cristatus is a thermophil species, whereasB. dalmatinus may be thermophobe.B. sanguinolentus, B. pavo, B. sphinx, andB. dalmatinus prefer habitats exposed to the sunlight;B. gattorugine andB. zvonimiri inhabit shadow biotopes. One can findB. galerita, B. trigloides, andB. cristatus at the surf-stage normally, whereasB. sphinx, B. canevae, andB. gattorugine are facultative inhabitants of this biotope. The vertical distribution depends on wave-action and, in part, on light. The main escape direction is upward to the water surface by most species inhabiting the surf-stage, downward byB. gattorugine andB. zvonimiri, and laterally by the other species examined. Morphological adaptations to the habitat in the surf-stage are indicated by the round or slightly depressed form of the body, and by the strong rays of the pectoral, pelvic and anal fins. None of theBlennius species examined exhibits ecological requirements similar to those of another species. It is probable that the striking specific radiation of the genusBlennius is rendered possible by the availability of different biotopes and microclimates.
Includes vita. Original publication date: 1968 ; photocopy date: 1970. "68-17,467." Includes bibliographical references (leaves 270-276). Thesis (Ph. D.)--University of California, 1968. Photocopy.
Thesis--University of California, Los Angeles. Microfilm of typescript.
Thesis (Ph. D.)--University of Arizona, 1975. Includes bibliographical references (leaves 141-147). Photocopy of typescript. 28 cm.
Typescript. Thesis--University of Maryland, College Park. Vita. Includes bibliographical references.
Twenty species of barnacles are now known from Fiji as a result of recent collecting. The barnacle fauna has Malaysian affinities, but there are no endemic species. Brief descriptions and notes on habitats are given. The effects of erosion on the shell are described for the common intertidal species. The distribution patterns of the common intertidal species, except for those of the coral-boring barnacles, are described; and from these the influence of environmental factors on barnacle distribution is inferred. By determining upper lethal temperatures, recording a few environmental temperatures, and comparing these with similar information on temperate barnacles and shores, I have concluded that high temperatures could be a deterrent to the existence of large numbers of barnacles on sun-exposed surfaces of tropical shores. In shaded conditions barnacles can, however, occupy most of the available surface.
I. The purpose of this study was to determine whether male blennies are attracted to or repulsed by neighboring prior residents. In a previous study of prior residency, I found that the newcomer often was physically attacked and chased. This obscured the question of whether the newcomer initially was attracted to the resident. In the present study, the two animals were separated by a transparent, perforated barrier so that physical contact was impossible. The newcomer could choose between approaching the resident and utilizing the enclosure within his view or withdrawing and using an enclosure out of sight of the resident. 2. A second variable, that of the effect of prior social experience, was also tested. The newcomers were separated into two classes depending on whether they dominated or were subordinate in previous social encounters. The effects of these two variables were separated by means of a 2 X 2 factorial design. Four measures of approach/ withdrawal to the prior resident and three measures of enclosure choice were employed. 3. Those newcomers that had dominated in previous encounters approached the prior resident. They did not demonstrate a preference for either of the enclosures during the observation period (30 minutes). A measure covering a longer period did reveal a preference for the enclosure near the resident. 4. The subordinate fish neither approached nor avoided the resident. They did use the enclosure farther away from the prior resident more than they used the other enclosure, hower.
Habitat and resource partitioning between two species of Acanthemblemaria (Pkces : Chaenopsidae)
- D W Greenfield
- T A Kl
- Greenfield
GREENFIELD, D. W. KL T. A. GREENFIELD, 1982: Habitat and resource partitioning between two species of Acanthemblemaria (Pkces : Chaenopsidae), with comments on the chaos hypothesis.
The Bahaman species of emblemariid blennies.
- Böhlke J. E.
BOHLKE, J.E., 1957: The Bahaman species of ernblemariid blennies. Proc. Acad. Nat. Sci. Philadelphia, 109: 25-57.
Resource utilization in some rocky shore fishes in the Gulf of California The barnacles of Fiji, with observations on the ecology of barnacles on tropical shores
- K R Critchlow
CRITCHLOW, K. R., 1972: Resource utilization in some rocky shore fishes in the Gulf of California. Ph. D. thesis, Wniv. Calif., Los Angeles, W.S.A.; 133 pp. FOSTER, B. A., 1974: The barnacles of Fiji, with observations on the ecology of barnacles on tropical shores. Pac. Sci., 28: 35-56.
New genera and species of fishes from Tortugas, Florida.
- Longley W. H.