Characterization of microsatellite loci for the detection of temporal genetic shifts within a single cohort of the brown demoiselle,Neopomacentrus filamentosus

Neopomacentrus filamentosus, a common damselfish on the Indo–Australian archipelago, undergoes significant shifts in size and mitochondrial genetic structure upon larval settlement and metamorphosis to juvenile stages. We characterized five polymorphic microsatellite loci in order to study temporal genetic shifts within a single generation of N. filamentosus sampled first as larval settlers then again as demersal juvenile recruits. All loci were extremely polymorphic and exhibited high levels of heterozygosity. While all loci from the larval samples conformed to Hardy – Weinberg expectations, significant heterozygote deficiencies were seen in two loci in the juvenile samples, likely due to extreme size‐selective mortality imposed post‐settlement.     

Behaviour of the female beaugregory damselfish (Stegastes leucostictus)

Much less is known about the behaviour of female beaugregory damselfish than about males of the species. This study was initiated to determine behavioural patterns and interactions of female beaugregories on the back reef of Discovery Bay Marine Laboratory, North shore of Jamaica. Females fed, patrolled, and chased intruders in a significantly larger area and ate significantly more per 15-min observation period than did males. Males spent significantly more time patrolling their territories and chased significantly more total intruders than did females. However, this difference in total chases comes from the fact that males chased the bluehead wrasse, an egg predator, significantly more often than did females while all other species of intruder were chased the same by both sexes. The distance that females travelled from their homesite to court was significantly positively correlated to female body length. This increased distance travelled may relate to mate assessment. Female beaugregory damselfish may be able to be more selective in their choice of mate with increased size and distance travelled.     

Maritime Legislation of Mainland China and Taiwan: Developments,Comparison, Implications,and Potential Challenges for the United States

In January 1998, Taiwan promulgated the Law of the Republic of China (ROC) on the Territorial Sea and the Contiguous Zone and the Law of the Republic of China on the Exclusive Economic Zone (EEZ) and the Continental Shelf, both of which came into force on January 21, 1998. On June 26, 1998, China adopted the Law of the People's Republic of China on the Exclusive Economic Zone and the Continental Shelf, which is the most significant maritime legislation since its 1992 Law on the Territorial Sea and the Contiguous Zone. This article studies the recent maritime legislation developments in Mainland China and Taiwan, the differences and similarities between the two sets of laws, their implications for the Asia-Pacific region, and the potential challenges for the United States.     

SOUND PRODUCTION IN THE BLUE-GREEN DAMSELFISH,CHROMIS VIRIDIS (CUVIER, 1830) (POMACENTRIDAE)

ABSTRACT

Sound production is widespread in coral reef fish of the family Pomacentridae. As commonly found in other teleosts, damselfish emit calls in agonistic and courtship contexts. In this paper, evidence of sound production by the blue-green damselfish Chromis viridis is presented for the first time. The recorded sounds consisted of clicks produced during agonistic interactions.     

Landscape structural analysis of the Lençóis Maranhenses national park: implications for conservation

Our work evaluated the anthropic effects on the landscape structure of the Lençóis Maranhenses National Park (LMNP) and its Buffer Zone, and proposed strategies for the region’s conservation. LMNP is an important protected area in Brazilian north coast which protects a unique wetland ecosystem composed of sand dunes fields and a coastal vegetation called restinga. Supervised mapping of LMNP and a surrounding buffer of 3 km was carried out through high resolution and fine scale (1:5000) satellite images. The mapped area was subdivided in 1000 ha hexagonal Analysis Units (AU) and the following landscape metrics were calculated for each one of them: cover area (CA) of each soil cover class - dune fields (CA-DUNES), water bodies (CA-WATER), dense restinga (CADENSE), scattered restinga (CA-SCATTER), grassland (CA-SANDY), mangroves (CA-MANG), anthropogenic activity (CA-ANTRO) and, secondary vegetation (CA-SECOND); Landscape Shannon Diversity Index (SHDI), and; percentage of native vegetation cover (NV−COV). Pearson correlations were performed between the CA of each class and SHDI to identify the classes most correlated to CA-ANTRO. Our results showed that anthropic classes (crops, trails, and villages) had a stronger correlation (Pearson Correlation, r ≈ 0.65) with phytophysiognomies of dense restinga, secondary vegetation and SHDI, thus indicating that the land use conversion occurs in dense restinga areas and promotes vegetation secondarization, as well as increasing fragmentation. At least, 42% of the dense restinga habitats was destroyed due to human activities. Five conservation and restoration strategies were proposed in a local scale depending on the percentage of native vegetation cover on each AU, from the most to less conserved: (a) only conservation; (b) conservation with management; (c) management; (d) management and restoration; and, (e) restoration. The implementation of Agroforestry Systems with agro-successional restoration goals was recommended as an alternative for land use.     

Potential feedback between coral presence and farmerfish collective behavior promotes coral recovery

Stable between‐group differences in collective behavior have been documented in a variety of social taxa. Here we evaluate the effects of such variation, often termed collective or colony‐level personality, on coral recovery in a tropical marine farmerfish system. Groups of the farmerfish Stegastes nigricans cultivate and defend gardens of palatable algae on coral reefs in the Indo‐Pacific. These gardens can promote the recruitment, growth, and survival of corals by providing a refuge from coral predation. Here we experimentally evaluate whether the collective response of farmerfish colonies is correlated across intruder feeding guilds – herbivores, corallivores and egg‐eating predators. Further, we evaluate if overall colony responsiveness or situation‐specific responsiveness (i.e. towards herbivores, corallivores, or egg‐eaters in particular) best predicts the growth of outplanted corals. Finally, we experimentally manipulated communities within S. nigricans gardens, adding either macroalgae or large colonies of coral, to assess if farmerfish behavior changes in response to the communities they occupy. Between‐group differences in collective responsiveness were repeatable across intruder guilds. Despite this consistency, responsiveness towards corallivores (porcupinefish and ornate butterflyfish) was a better predictor of outplanted coral growth than responsiveness towards herbivores or egg‐eaters. Adding large corals to farmerfish gardens increased farmerfish attacks towards intruders, pointing to possible positive feedback loops between their aggression towards intruders and the presence of corals whose growth they facilitate. These data provide evidence that among‐group behavioral variation could strongly influence the ecological properties of whole communities.     

A new hypothesis for species coexistence: male–male repulsion promotes coexistence of competing species

We propose a new hypothesis for species coexistence by considering behavioral interactions between individuals. The hypothesis states that repulsive behavior between conspecific males (male–male repulsion) creates space for competing species, which promotes their coexistence. This hypothesis can explain the coexistence of two competing species even when their ecological niches completely overlap in spatially homogeneous environments. In addition, the mechanisms underlying such behavior might play a role in enabling the coexistence of two species immediately after speciation, with little or no niche differentiation, as in the case of cichlid fish communities, for example. Although there is limited evidence supporting this hypothesis, it can nevertheless explain the occurrence of species coexistence and biodiversity, which cannot be explained by previous theories.     

Direct Development of the Visual System of the Coral Reef Teleost, The Spiny Damsel, Acanthochromis polyacanthus

Unlike most marine teleosts, the coral reef-dwelling spiny damsel, Acanthochromis polyacanthus, lacks a pelagic larva dispersal phase and represents one of few examples of self recruitment onto a natal reef by a marine teleost immediately after hatching. Benthic eggs are protected by the parents, and upon hatching the young remain under parental care for several months. Visual morphogenesis of spiny damsel embryos and juveniles was examined to evaluate the potential visual capabilities of the young after emergence onto the reef. The optic primordia were visible in the embryo as hollow spheres of undifferentiated neuroblasts 2 days after fertilization (daf). Visual morphogenesis proceeded rapidly thereafter in the embryo such that at hatching (between 10 and 12daf) gross visual morphology was consistent with that reported in the majority of juvenile marine teleosts, reflecting direct development of the retina of the spiny damsel within the egg. At hatching, the outer nuclear layer comprised 2 classes of photoreceptors; cones and rods. Tangential sections of the retina revealed a square cone mosaic in which 4 double cones surrounded a single cone. This arrangement remained unchanged in all later life history intervals examined. Absolute eye size was large compared to larvae of marine pelagic spawners. Eye and lens diameters increased from 0.69 and 0.23mm, respectively, on the day of hatching (12daf), to 3.77 and 1.52mm, respectively, in a fish 131daf. Angular density of cones increased from 0.25 cones 10 visual arc^–1 in an embryo 8daf, to 1.14 cones 10 visual arc^–1 in a fish 131daf, demonstrating the potential for significant increase in spatial resolution with increasing eye size. Convergence ratios of cones to ganglion cells remained relatively constant from the time of hatching, suggesting that the determinate ganglion cell photopic receptive field was established early in development. The increase in the convergence ratios of rods: ganglion cells from 1.4 in the late stages of embryogenesis (10daf; 2 days prior to hatching) to 4.9 in a fish 103daf, demonstrated increasing scotopic ganglion cell receptive field size, with increasing age. This was a result of rod cell addition with growth. An increase in the angular density of rods from 0.18 rods 10 visual arc^–1 in an embryo 8daf, to 4.07 rods 10 visual arc^–1 in a fish 131daf, and the increase in mean scotopic light path-length from 13.3±1.1m in an embryo 8dpf, to 55±5.2m a fish 22dpf, collectively indicate the potential for increasing scotopic sensitivity during growth. On the basis of visual morphology it is predicted that newly hatched spiny damsel juveniles have substantially greater visual capabilities than first feeding larvae with a pelagic dispersal phase. In addition, we propose that the developmental trajectory of the spiny damsel is different from that of pelagic dispersing larvae and does not simply reflect displacement along a common developmental continuum by an extended embryonic duration.     

Why do female Lesser Spotted Eagles ( Aquila pomarina ) visit strange nests remote from their own?

There is very little confirmed information on the social organisation of breeding Lesser Spotted Eagle populations, the turnover rate of adults, and their nest-site and partner fidelity. According to established knowledge, however, breeding individuals are territorial and defend at least the immediate vicinity of the nest site against their own species. It has further been thought that females rearing young, as with the females of other raptor species, remain within a radius of only a few kilometres of their eyrie. Using GPS satellite telemetry and DNA microsatellite analysis (DNA STR typing), we were able to disprove this prevailing hypothesis. A satellite-tracked female flew over 50 km away from her eyrie (D) in at least two different directions and visited at least one other occupied eyrie (T). It was also established that at least two strange females arrived at her eyrie, which contained young, from as far away as 57 km, and probably remained there for some considerable time. The pool of alleles represented at the different loci analysed, as well as the distribution of these alleles among the individuals, excludes the possibility that these females could be sisters or even half-sisters. Visits of strange eagles at this eyrie were also confirmed by direct observation. It can therefore be assumed that males only exhibit territorial behaviour towards their own sex and not towards strange females and that females do not exhibit territorial behaviour towards other females; but all these assumptions must be confirmed by further studies. For the first time it could be proved by means of microsatellite analysis that almost all females studied used the same breeding site for 2 consecutive years. The longest established period in which both partners of a pair remained at the same breeding site was 3 consecutive years.     

Nest guarding in a damselfish: evidence of a role for parasites

A potential effect of parasitism on male egg loss while guarding was tested using damselfish Stegastes planifrons . Despite an apparent low energetic cost of the parasite on the male condition, there was a significant positive relationship between egg loss and parasite load. These data provide the first evidence that parasites could play a role in male guarding behaviour. The effect of the parasite could have resulted in low male condition compensated by an increase in filial cannibalism or in a lesser ability to protect the nest from predators.