The elusive Mediterranean gobies (Actinopteri: Gobiidae and Oxudercidae), their geographic pattern and the discussion on the rareness of Mediterranean fishes

ABSTRACTAimsClimate change is expected to bolster opportunities for alien species' establishment and spread. In Europe, alien C4 grass species have the potential to benefit from a changing climate, being better adapted to higher temperatures and heat stress. Our aim was to compile an up‐to‐date inventory of alien C4 grass species in Europe, to find information about their distribution and country‐ and region‐wise statuses, to identify the most widespread and high‐risk species, and the most invaded habitat types, and to draw the temporal trends of their European establishment.LocationEurope.MethodsWe used the standard systematic literature review methodology to identify relevant publications and online plant distribution databases to get an up‐to‐date list of alien C4 grass species in Europe. We aimed also to gather information on (1) their current country‐ and region‐wise distribution; (2) alien status in each country (casual, naturalised, invasive); (3) the most widespread and high‐risk species; (4) native climatic zones and habitat preferences of each species in European countries; and (5) temporal distribution patterns of the identified species.ResultsWe detected 133 alien C4 grass species across Europe, with the highest number of species in western European countries (103 species) and the lowest in northern Europe (69 species), with considerable overlap amongst regions. Southern Europe stands out with the highest number of naturalised (55) and invasive (21) species compared to other regions, while northern Europe has the highest number of casual species (53). We identified the most widespread and high‐risk species, including those from tropical and subtropical climatic zones, which pose the highest invasion risks. These species predominantly occur in ruderal and anthropogenic habitat types, but also in natural habitat types, especially in grasslands. Regarding temporal trends, we detected an alarming increase in the establishment of tropical C4 grasses in Europe in recent decades.ConclusionsMany European countries already harbour a high number of C4 grass species, but with different alien statuses. Besides climate and invasion potential, human activities are also important factors in the ongoing invasion process of alien C4 grass species. Collective actions are required to halt this alarming biodiversity problem.

Much research has focused on identifying traits that can act as useful indicators of how habitat loss affects the extinction risk of species, and the results are mixed. We developed 2 simple, rapid-assessment models of the susceptibility of species to habitat loss. We based both on an index of range size, but one also incorporated an index of body mass and the other an index combining habitat and dietary specialization. We applied the models to samples of birds (Accipitridae and Bucerotidae) and to the lemurs of Madagascar and compared the models' classifications of risk with the IUCN's global threat status of each species. The model derived from ecological attributes was much more robust than the one derived from body mass. Ecological attributes identified threatened birds and lemurs with an average of 80% accuracy and endangered and critically endangered species with 100% accuracy and identified some species not currently listed as threatened that almost certainly warrant conservation consideration. Appropriate analysis of even fairly crude biological information can help raise early-warning flags to the relative susceptibilities of species to habitat loss and thus provide a useful and rapid technique for highlighting potential species-level conservation issues. Advantages of this approach to classifying risk include flexibility in the specialization parameters used as well as its applicability at a range of spatial scales.

Ninety-three species of bony fishes were caught in 4 seasonal bottom-trawl surveys carried out between July 1986 and May 1987 on the outer shelf and upper slope (124 to 587 m depth) along the southern Brazilian coast (30°40' to 3430' S). On the outer shelf (< 179 m), the demersalpelagic species Trichiurus lepturus, Trachurus lathami, Cynoscion guatucupa, Scomber japonicus, and Thyrsitops lepidopoides predominated and also to a lesser degree the demersal benthonic Umbrina canosai and Mullus argentinae. Antiyonia capros and Priacanthus arenatus were found associated with the relic coral hard bottoms of the shelf break (180 to 249 m). Further offshore, the demersal-pelagic species Ariomma bondi and Zenopsis conchifera and the demersal benthonic species Polyprion americanus and Helicolenus lahillei were abundant, both associated with rocky bottoms. The macrourids Coelorinchus marinii and Malacocephalus occidentalis characterized deep-water hauls p 4 5 0 m). Frequent and widespread, but less abundant in the catch, were Polymixia lowei, Urophycis mystacea and Merluccius hubbsi. Mean total catch (kg h-') decreased 6-fold and the number of species by more than half along the depth range, with a sharp step at 350 m. Both catch and number of species were slightly higher in the winter cruises. Most species occurred in both winter and summer-autumn cruises, but, with increasing depth, the relative abundance of species that occur year-round decreased, whereas fishes that occur mostly in winter increased. The catch of demersal-pelagic fish decreased sharply below 350 m and differed little among seasons; catches of demersal-benthonic fish were more evenly distributed across the depth range and were larger in winter and spring. The high number of species on the shelf break may be attributable to the higher variety of soft and consolidated substrates and the overlapping of different water masses along the water column. The north-south shift of the western boundary of the Subtropical Convergence appears to be mainly responsible for the seasonal changes in abundance of the species.

In the last 10 years, several studies have been carried out on the fish fauna of the Ustica Island marine reserve, yet no investigation was specifically addressed to the cryptobenthic fish assemblage. The first task of this study, conducted along the shallow rocky reefs of Ustica, was to determine the species composition, diversity and relative density of the resident cryptobenthic fishes. Furthermore, we aimed to assess the effects of some macro- and microscale habitat characteristics on the distribution pattern of fishes. In particular, the effect of predator density was indirectly evaluated by comparing density data collected within and outside the integral reserve zone. Overall, 20 species belonging to Blenniidae, Gobiidae, Tripterygiidae, Scorpaenidae and Gobiesocidae were recorded. Gobius bucchichi, Scorpaena maderensis, Tripterygion delaisi, T. melanurus and T. tripteronotus were the numerically dominant and most common species. The effects of zone (i.e. of predator density), bottom type and depth on species richness, diversity and evenness were not significant. A greater total fish density was observed on stones compared with rocky cliff and plateau, but only in the shallowest depth range. At level of single species, G. bucchichi was more abundant inside than outside the integral reserve, but only on stones and at 0–2 m depth range. Density of G. bucchichi was generally higher on stones than on rocky cliffs or plateau and between 0 and 5 m depth, although these differences were not always significant. T. delaisi was conversely more abundant in the deepest stratum (7–10 m). Canonical analyses demonstrated that bottom type and depth influenced significantly the fish assemblage structure. The observed differences in the assemblage structure relied mainly upon the dominant species. T. tripteronotus was mainly associated with rocky plateau and the intermediate depth range (3–5 m), whereas S. maderensis, T. melanurus and Lipophrys trigloides inhabited preferentially the rocky cliffs. At microscale level, the habitat choice of the investigated species was almost entirely based on whether the substrate was either vegetated or composed of bare rock. T. delaisi and T. tripteronotus were associated with substrata covered by algae, whilst G. bucchichi, S. maderensis and T. melanurus preferred bare rock bottoms. In some species, the electivity indices for the less abundant type of cover, measured at different spatial scale, changed accordingly. For instance, the smaller the size of the sampled area, the higher was the intensity of the association between G. bucchichi and Anemonia viridis.

Species composition and distributions of mesopelagic fishes over the slope of the north-central Gulf of Mexico

Gravity data in the eastern Mediterranean area have been compiled from Woods Hole Oceanographic cruises of the R/V Chain in 1964 and 1966, and supplemented by other shipboard and land measurements. Over most of the area, free-air anomalies are negative and Bouguer anomalies are consistently lower, by 50 to 100 mgal, than in the western Mediterranean. Broad negative free-air anomalies (−80 to −240 mgal) and low positive Bouguer anomalies (0 to 80 mgal) follow an arcuate zone, concave northward, south of Crete from western Greece to the Rhodes abyssal plain. Relatively high anomalies (free-air anomaly as high as −60 mgal and Bouguer anomaly of +100 to +140 mgal) centered over the Anaximander seamounts separate the arcuate low south of Crete from a similar trend south of Cyprus that gradually becomes less distinct toward northern Syria. Cyprus is characterized by free-air anomalies greater than 100 mgal, Bouguer anomalies of from +100 to +250 mgal, and some of the world9s largest positive isostatic anomalies (as great as +173 mgal). A crustal-structure model was constructed for a profile south from Turkey, approximately along long. 31°E., toward Egypt. The simulated structure showed a range in depth to the top of the mantle from 23 km beneath the outer margin of the Nile Cone to 34 km beneath the axis of the Mediterranean Ridge. A free-air anomaly gradient of about −1.2 mgal/km to the north over the southern margin of the Mediterranean Ridge corresponds to a downward slope on the crust-mantle interface of about 7° to the north. The thickening of the crust by almost 50 percent north of 34°N. is interpreted as largely due to underthrusting of Mediterranean crust beneath Cyprus, the Anaximander Mountains, and Turkey. A concomitant thick accumulation of sediment may have further downwarped the crust beneath the Mediterranean Ridge.

The FishMed database provides traits, phylogeny, current and projected species distribution of Mediterranean fishes, and associated sea surface temperature (SST) from the regional oceanic model NEMOMED8. Data for the current geographical distributions of 635 Mediterranean fish species were compiled from a published expert knowledge atlas of fishes of the northern Atlantic and the Mediterranean (FNAM) edited between 1984 and 1986 and from an updated exotic fish species list. Two future sets of projected species distributions were obtained for the middle and end of the 21st century by using an ensemble forecasting approach for 288 coastal Mediterranean fish species based on SST according to the IPPC/SRES A2 scenario implemented with the Mediterranean climatic model NEMOMED8. The functional part of the database encompasses 12 biological and ecological traits (maximal and common lengths, vertical distribution, habitat, migration type, mode of reproduction, sex shift, semelparity, diet type (larvae and adults), social behavior, species origin, and depth) for the 635 fish species. To build the phylogeny we inferred the timing and geographic origins of Mediterranean teleost species diversity using nucleotide sequences collected from GenBank including 62% of Mediterranean teleost species plus nine outgroups. Maximum likelihood Bayesian phylogenetic and dating analyses were calibrated using 20 fossil species. An additional 124 fish species were grafted onto the chronogram according to their taxonomic affinity to obtain a phylogenetic tree including 498 species. Finally we also present the associated SST data for the observed period (1961–1980) and for the middle (2040–2059) and the end of the 21st century (2080–2099) obtained from NEMOMED8 according to the IPCC A2 scenario. The FishMed database might be of interest in the context of global anthropogenic changes as coastal Mediterranean ecosystems are currently recognized as one of the most impacted ecosystems on earth.

Determining suitable fish to monitor plastic ingestion trends in the Mediterranean Sea

Macroalgae are an important and diverse component of tropical inshore reefs, providing a range of ecological and functional services. Most of the research emphasis has focused on the negative effects of increased macroalgae on coral reefs to the growth and persistence of corals and fishes. However, on undisturbed reefs, macroalgal beds provide important habitats for newly settled fishes, many of which have ontogenetic changes to coral reefs and replenish adult populations that help control macroalgal growth. The few studies that have investigated macroalgal associations of juvenile fishes have treated macroalgae as a single entity. In doing so, any associations of fishes with taxonomic or functional groups cannot be discerned. The objective of this thesis was to undertake observational and experimental studies to investigate the patterns and mechanisms of habitat selection and preferences in algal-associated juvenile fishes on coastal reefs. In Chapter 2, I investigated the availability, use and selectivity of microhabitats on the reef flat of an inshore reef by recently settled coral reef fishes. Fish and benthic communities were quantified along three 50m transects at each of six reef flat sites along the leeward side of Orpheus Island, an inshore island on the central Great Barrier Reef (GBR). Benthic communities were quantified using the point-intercept method, recording the benthos directly underneath the transect every 0.5m. Recently settled fish were surveyed within a 2m belt along each transect. All recently settled fishes were identified to species, and the microhabitat they were associated with was recorded. A total of 22 species of recently settled fish were recorded across all transects, with the majority of the species being herbivorous as adults. Examination of the microhabitat preferences of the six most abundant species revealed that the two herbivorous rabbitfish species, Siganus lineatus and S. canaliculatus, appeared to associate with large fleshy macroalgae (namely Padina and Sargassum). In contrast, three herbivorous damselfishes, Pomacentrus wardi, P. adelus and P. chrysurus, and the invertebrate feeding cardinalfish Apogon cookii showed no apparent selection for any of the microhabitats examined. These findings suggest that macroalgae are important habitats for some newly settled coral reef fishes, and the availability and composition of macroalgae may shape juvenile populations. Both habitat selection at settlement and/or post-settlement processes may contribute to the establishment of these patterns. The objective of Chapter 3 was to investigate the specific habitat and olfactory preferences of two rabbitfishes (S. lineatus and S. canaliculatus) and two herbivorous damselfishes (P. wardi and P. adelus) at settlement. Naive settlement-stage fishes were collected in light traps and used in a series of aquarium-based settlement choice experiments in which an individual larva was introduced into the centre of a 500L aquarium and allowed to choose among four habitat options. The fishes were released overnight and their associations with the four habitats recorded the following morning. Four separate habitat-choice experiments were conducted, each with four different substratum options: (1) benthic habitats (live coral, dead coral, macroalgae, coral rubble), (2) macroalgal species (Sargassum, Padina, Galaxaura, coral rubble), (3) macroalgal density (8, 4, 1, 0 Sargassum thalli) and (4) macroalgal height (30, 20, 10, 0cm Sargassum). In addition, the role of olfaction was investigated using a 2 channel-choice flume chamber, pairing a benthic substrate water cue to the off-reef control cue (1 km from the nearest reef). The aquarium trials showed that both rabbitfish species preferred macroalgae in experiment 1 and the highest density Sargassum patch in experiment 3. The two rabbitfishes also differed in their habitat preferences as only S. canaliculatus preferred Sargassum in experiment 2 and S. lineatus preferred the tallest Sargassum patch in experiment 4. In contrast, neither damselfish species displayed any preferences among the habitats present. The olfactory trials revealed significant but weak attractions to various chemical cues from benthic microhabitats, however, these varied among species and are unlikely to be biologically significant. It is apparent that juvenile rabbitfishes have strong innate preferences for macroalgae at settlement, however, species-specific preferences for macroalgal species and habitat features may affect the distribution of juveniles on the reef. In summary, macroalgae appear to provide important settlement and juvenile habitats for at least the two rabbitfishes species examined herein, and given the prevalence of juvenile fishes in this habitat, it is likely that such preferences may be more widespread. It is unclear why these early life stages are using macroalgae, but they may be associated with the provision of refugia from predation, or enhanced food supply as these fishes transition from a carnivorous to herbivorous diet. Interestingly, many studies have focused on the role of herbivorous rabbitfishes in removing macroalgae from coral reefs, yet the results of this thesis highlight that these same fishes are dependent on macroalgae at a critical life stage. Clearly, further investigations are required to elucidate the importance of macroalgae to reef fishes at settlement, and potentially other life stages.

Threshold responses and relationships between waterbird distribution and habitat factors at Shengjin Lake, China

Recent deep‐sea explorations in the South Pacific have documented around New Caledonia the most diverse fauna of gastropods of the family Volutomitridae anywhere in the world. Fourteen species (nine new, two remaining unnamed) are recorded, all essentially confined to the 250–750 m depth range. The high number of species in the New Caledonia region does not appear to be an effect of sampling intensity, but appears to result from four factors: regional spatial heterogeneity, frequency of hard substrates, syntopy, and a historical heritage shared with Australia and New Zealand, which until now ranked as the major centre of volutomitrid diversity. In the New Caledonia region, volutomitrids show a marked preference for hard bottoms and up to three species may co‐occur in the same dredge haul. Many species appear to have extremely narrow geographical distributions within the region (e.g. a single seamount or a single submerged plateau); conversely, Microvoluta joloensis, the only non‐endemic volutomitrid present in New Caledonia, ranges from the Mozambique Channel to Tonga.

Abstract- A species' habitat preference is intcrpretablc both as a response to present-day conditions and as a result of evolutionary response to historical conditions. The taxon cycle and taxon pulse have been proposed as hypotheses that allow prediction of patterns of habitat specialization within a lineage. Both are based on common assumptions: (1) habitat specialization is largely irreversible in a lineage, (2) ecological specializations arise in a center of origin, and (3) dispersal events leading to current distributions can be ascertained. Eight taxa of Antillean, Mexican, and Central American Carabidae, for which cladistic hypotheses of relationship have been proposed, are used to test the generality of the taxon cycle and pulse. The patterns of habitat utilization predicted by the taxon cycle and taxon pulse hypotheses are tested by comparing cladistic transformations of habitat preference to randomly generated patterns of data generated under a null hypothesis. Evolutionary changes in habitat are interpreted using Camin-Sokal coding, which assumes irreversible habitat shifts and a predetermined ecological ground state (assumptions of the taxon cycle and taxon pulse). An observed pattern is considered to demonstrate the taxon cycle or pulse when it results in an explanation of the habitat shifts that is more parsimonious than 95 % of the randomly generated patterns. Of the eight carabid groups, only one exhibits a statistically significant pattern supporting the taxon cycle and pulse. The failure of the taxon cycle and pulse as generally predictive hypotheses may be due to historical changes in climate that permit episodes of range expansion for species previously restricted to small ranges, and habitat shifts and specialization that do not progress in a linear transformation series. Habitat shifts are also analyzed using Farris optimization, resulting in the most parsimonious transformation series of habitats, subject to a predefined ordering of habitats, while allowing reversals. Significance of an observed pattern of habitat shifts under Farris optimization implies habitat constancy relative to cladogenesis, and step-wise changes in habitat preference. Two of the eight groups exhibit significant patterns of habitat utilization under Farris optimization, indicating that vicariance of areas of like habitat has been the predominant factor generating species diversity in these groups. The other groups do not exhibit habitat constancy, suggesting rapid changes in habitat preference relative to speciation.

First data on benthic and fish communities from the Mid-Atlantic Ridge, 16°40′− 17°14′N

We examined deep-sea epibenthic sledge isopod data from the Atlantic sector of the Southern Ocean (SO) (depth range=742–5,191 m). Samples were taken during the expeditions EASIZ II (ANT XV-3) in 1998 and ANDEEP I and II (ANT XIX3/4) in 2002. A total of 471 isopod species were recorded from 28 sites. The species richness of the epibenthic sledge samples was highly variable (6–82 species). Species richness was highest at site 131-3 in 3,053 m depth in the north-eastern Weddell Sea. The highest numbers of species were sampled in the middle depth range and lower species richness was found in the shallower and deeper parts of the study area. Depth is suggested to explain isopod species richness better than both latitude and longitude. Between 58°S and 65°S, the number of species ranged from 9 to 82 (mean=35.9). Further south in the Weddell Sea, between 73°S and 74°S, species richness was lower and the number of species ranged from 6 to 35 (mean=19.2). With regard to longitude, the highest species richness (up to 82 species) was found between 50°W and 60°W in the area of the South Shetland Islands and around the Antarctic Peninsula, while numbers did not exceed 50 species in the eastern Weddell Sea. The haul length, ranging from 807 to 6,464 m, was positively correlated with depth; however, there was no linear relationship between haul length and species richness. We therefore suggest that depth was the most important factor explaining isopod species richness. However, only 28 sites were visited and the statistical power is thus limited. Sampling in the deep sea is expensive and time consuming and as yet this is the best isopod data set available from the Atlantic sector of the SO. Future expeditions are therefore important to better explain the current patterns of benthic diversity in Antarctica.

Butterfly species are one of the indicator groups for biodiversity change and habitat monitoring. However, studies on butterfly species' habitat and altitude preferences have rarely been evaluated. A study was carried out on the species diversity of butterfly fauna in different habitats and altitudes from Kozluk district of Batman Province. The survey was conducted in 43 locations between 2020-2021. Evaluations were executed for 1.982 butterfly samples collected from the research area. 103 species are diagnosed in 7 families of butterfly; Argynnidae: 15, Libytheidae: 1, Lycaenidae: 34, Papilionidae: 4, Pieridae: 15, Satyridae: 19, Hesperiidae: 15. Among them, 64 species are newly recorded in Kozluk and 34 species in Batman. The species of Libythea celtis (Laicharting, 1782), together with its family Libytheidae, has been added to the fauna of Batman, and the number of butterfly species in Batman increased from 90 to 124. The altitude and habitat preferences of the specimens in the research area and the number of species in the locations of the families are presented and discussed. The majority of the species are determined in oak forests and riverside biotopes. Geçitaltı is the location with the highest number of species. The butterflies are mostly detected between 600-1000 m altitudes with a rate of 72% in the research area. This study is utilizable both to the specification of the distribution areas of the species and to the learning of their ecology.