Heterochrony and the evolution of the longjaw mudsucker (Gobiidae, Teleostei).

Although longjaw mudsucker (Gillichthys mirabilis, Gobiidae) has been studied extensively for its ability to occupy low-oxygen environments, few studies have addressed the evolution of its exceptionally elongated jaws that extend posteriorly beyond the gill opening in large adults. In this study, the ontogeny of the maxillae of G. mirabilis, Gillichthys seta, and the out-group species Eucyclogobius newberryi was studied within the heterochrony framework using digitized landmarks and caliper measurements. The results show that the maxilla of both species of Gillichthys evolved via acceleration (increased growth rate) and that of G. mirabilis via hypermorphosis (continued growth to a larger body size); two forms of peramorphosis. This is in contrast to earlier studies that concluded that G. seta is paedomorphic. We were unable to confirm an earlier hypothesis of sexual dimorphism in the jaw length of G. mirabilis. The evolution of the elongated jaws and associated large buccopharyngeal membrane in G. mirabilis is hypothesized to increase the surface area for gas exchange during aerial respiration and may also serve to amplify the aggressive gaping display as observed in other fishes.

Laboratory-based measures of temperature preference and metabolic thermal sensitivity provide insight into the habitat utilisation of juvenile California horn shark (Heterodontus francisci) and leopard shark (Triakis semifasciata).

Laboratory-based studies examining fish physiological and behavioural responses to temperature can provide important insight into species-specific habitat preferences and utilisation, and are especially useful in examining vulnerable life stages that are difficult to study in the wild. This study couples shuttle box behavioural experiments with respirometry trials to determine the temperature preferences and metabolic thermal sensitivity of juvenile California horn shark (Heterodontus francisci) and leopard shark (Triakis semifasciata). As juveniles, these two species often occupy similar estuarine habitats but display contrasting behaviours and activity levels - H. francisci are relatively sedentary, whereas T. semifasciata are more active and mobile. This study shows that juvenile H. francisci and T. semifasciata have comparable thermal preferences and occupy similar temperature ranges, but H. francisci metabolism is more sensitive to acute changes in temperature as expressed through a higher Q10 (H. francisci = 2.58; T. semifasciata = 1.97; temperature range: 12-24°C). Underlying chronic temperature acclimation to both warm (21°C) and cool (15°C) representative seasonal temperatures did not appear to significantly affect these parameters. These results are discussed in the context of field studies examining known distributions, habitat and movement patterns of H. francisci and T. semifasciata to better understand the role of temperature in species-specific behaviour. Juvenile H. francisci likely target thermally stable environments, such as estuaries that are close to their preferred temperature, whereas juvenile T. semifasciata metabolism and behaviour appear less dependent on temperature.

US county-level estimation for maternal and infant health-related behavior indicators using pregnancy risk assessment monitoring system data, 2016-2018.

BACKGROUND: There is a critical need for maternal and child health data at the local level (for example, county), yet most counties lack sustainable resources or capabilities to collect local-level data. In such case, model-based small area estimation (SAE) could be a feasible approach. SAE for maternal or infant health-related behaviors at small areas has never been conducted or evaluated. METHODS: We applied multilevel regression with post-stratification approach to produce county-level estimates using Pregnancy Risk Assessment Monitoring System (PRAMS) data, 2016-2018 (n = 65,803 from 23 states) for 2 key outcomes, breastfeeding at 8 weeks and infant non-supine sleeping position. RESULTS: Among the 1,471 counties, the median model estimate of breastfeeding at 8 weeks was 59.8% (ranged from 34.9 to 87.4%), and the median of infant non-supine sleeping position was 16.6% (ranged from 10.3 to 39.0%). Strong correlations were found between model estimates and direct estimates for both indicators at the state level. Model estimates for both indicators were close to direct estimates in magnitude for Philadelphia County, Pennsylvania. CONCLUSION: Our findings support this approach being potentially applied to other maternal and infant health and behavioral indicators in PRAMS to facilitate public health decision-making at the local level.

Molecular systematics of the New World clingfish genus Gobiesox (Teleostei: Gobiesocidae) and the origin of a freshwater clade.

The phylogenetic relationships between marine and freshwater members of the New World clingfish genus Gobiesox are investigated using both mitochondrial and nuclear sequence data. Phylogenetic hypotheses are derived from Bayesian and maximum parsimony analyses of a six-gene concatenated data set (2 mitochondrial and 4 nuclear markers; 4098bp). Gobiesox is paraphyletic, due to the inclusion of Pherallodiscus, in phylogenetic hypotheses resulting from all analyses and its two included species are reassigned to Gobiesox. Within the expanded genus Gobiesox, the freshwater species (G. cephalus, G. juradoensis, G. mexicanus and G. potamius) represent a monophyletic group that is nested inside of a paraphyletic marine group. Based on the monophyly of the freshwater clingfishes, a habitat transition from marine to freshwater is inferred to have occurred only once in the evolutionary history of the group (potentially in the mid-Miocene). Gobiesox is obtained as part of a larger clade of New World clingfishes, including also members of Acyrtops, Acyrtus, Arcos, Rimicola, Sicyases and Tomicodon equivalent to the subfamily Gobiesocinae. The phylogenetic hypotheses obtained are discussed briefly in relation to the two alternative classifications currently in use simultaneously for the Gobiesocidae. A rediagnosis and list of included species is provided for Gobiesox.

Improved resolution and a novel phylogeny for the Neotropical triplefin blennies (Teleostei: Tripterygiidae).

The triplefin blennies (Teleostei: Tripterygiidae) are a diverse group of small-bodied benthic fishes associated with rocky or coral reefs. The Neotropics contain four genera and 26 species, many of which have only been recently described. A recent molecular phylogeny (Lin and Hastings, 2013) contrasts with previous phylogenies based on morphology in recovering the four Neotropical genera as a single clade with respect to the Indo-Pacific genera; however, relationships within and among genera were poorly resolved. This study reports a novel topology based on an expanded seven-loci molecular dataset. Individual gene trees have poor resolution, but concatenated analyses show strong support for most nodes, likely due to emergent support from concatenation. Consistent with Lin and Hastings (2013), three of the Neotropical genera, Axoclinus, Enneanectes, and Crocodilichthys, form a well-supported clade, but relationships of the fourth (Lepidonectes) are not confidently resolved. The monophyly of Axoclinus is well supported, but Enneanectes is paraphyletic with the inclusion of Axoclinus and Crocodilichthys. Improved resolution allows for reinterpretation of the biogeography of the Neotropical Tripterygiidae. Broader taxon sampling is still necessary for resolving the relationships within Tripterygiidae globally.

Phylogeny and biogeography of a shallow water fish clade (Teleostei: Blenniiformes).

BACKGROUND: The Blenniiformes comprises six families, 151 genera and nearly 900 species of small teleost fishes closely associated with coastal benthic habitats. They provide an unparalleled opportunity for studying marine biogeography because they include the globally distributed families Tripterygiidae (triplefin blennies) and Blenniidae (combtooth blennies), the temperate Clinidae (kelp blennies), and three largely Neotropical families (Labrisomidae, Chaenopsidae, and Dactyloscopidae). However, interpretation of these distributional patterns has been hindered by largely unresolved inter-familial relationships and the lack of evidence of monophyly of the Labrisomidae. RESULTS: We explored the phylogenetic relationships of the Blenniiformes based on one mitochondrial (COI) and four nuclear (TMO-4C4, RAG1, Rhodopsin, and Histone H3) loci for 150 blenniiform species, and representative outgroups (Gobiesocidae, Opistognathidae and Grammatidae). According to the consensus of Bayesian Inference, Maximum Likelihood, and Maximum Parsimony analyses, the monophyly of the Blenniiformes and the Tripterygiidae, Blenniidae, Clinidae, and Dactyloscopidae is supported. The Tripterygiidae is the sister group of all other blennies, and the Blenniidae is the sister group of the remaining blennies. The monophyly of the Labrisomidae is supported with the exclusion of the Cryptotremini and inclusion of Stathmonotus, and we elevate two subgenera of Labrisomus to establish a monophyletic classification within the family. The monophyly of the Chaenopsidae is supported with the exclusion of Stathmonotus (placed in the Stathmonotini) and Neoclinus and Mccoskerichthys (placed in the Neoclinini). The origin of the Blenniiformes was estimated in the present-day IndoPacific region, corresponding to the Tethys Sea approximately 60.3 mya. A largely Neotropical lineage including the Labrisomidae, Chaenopsidae and Dactyloscopidae (node IV) evolved around 37.6 mya when the Neotropics were increasingly separated from the IndoPacific, but well before the closure of the Tethys Sea. CONCLUSIONS: Relationships recovered in this study are similar to those of earlier analyses within the Clinidae and Chaenopsidae, and partially similar within the Blenniidae, but tripterygiid relationships remain poorly resolved. We present the first comprehensive phylogenetic hypothesis for a monophyletic Labrisomidae with five tribes (Labrisomini, Mnierpini, Paraclinini, Stathmonotini and Starksiini). Global distributions of blenny genera included in our analysis support the evolution of a largely Neotropical clade whose closest relatives (clinids and cryptotremines) are temperate in distribution.

Long-term effectiveness of a multi-use marine protected area on reef fish assemblages and fisheries landings.

The Loreto Bay National Park (LBNP) is a large, multi-use marine protected area in the Gulf of California, Mexico, where several types of small-scale commercial and recreational fishing are allowed, but where less than 1% of the park is totally protected from fishing. The LBNP was created in 1996; its management plan was completed in 2000, but it was not effectively implemented and enforced until 2003. Between 1998 and 2010, we monitored reef fish populations annually at several reefs inside and outside the LBNP to measure the effects of the park on fish assemblages. We also evaluated reported fisheries landings within the LBNP for the same time series. Our results show that reef fish biomass increased significantly after protection at a small no-take site at LBNP relative to the rest of the park. However, the multi-use part of LBNP where fishing is allowed (99% of its surface) has had no measurable effect on reef fish biomass relative to open access sites outside the park boundaries. Reported fisheries landings have decreased within the park while increasing in nearby unprotected areas. Although the current partial protection management regime has not allowed for reef fish populations to recover despite 15 years as a "protected area," we conclude that LBNP's regulations and management have maintained the conditions of the ecosystem that existed when the park was established. These results suggest that community livelihoods have been sustained, but a re-evaluation of the multi-use management strategy, particularly the creation of larger no-take zones and better enforcement, is needed to improve the reef fish populations in the park in order to ensure sustainable fisheries far into the future. These recommendations can be applied to all multi-use MPAs in Mexico where ecosystem recovery is not occurring despite maintenance of fish stocks.

Chriolepis bilix, a new species of goby (Teleostei: Gobiidae) from deep waters of the western Atlantic.

A new species of seven-spined goby of the genus Chriolepis is described from four specimens from four widely separate western Atlantic localities (Little Bahama Bank; off southwestern Florida; Tobago Island; and northeastern Colombia) from depths ranging from 62 to 138 m. The species is distinct from all other western Atlantic species currently assigned to the genus Chriolepis in having a fully scaled body, the first two dorsal-fin spines greatly elongated in both sexes, especially so in females, and two anal-fin pterygiophores inserted anterior to the first haemal spine. It differs from members of the similar genus Varicus in having branched pelvic-fins rays, a longer fifth pelvic-fin ray and more numerous meristic elements. It closely resembles Chriolepis atrimelum, known from a similar depth at Isla del Coco in the eastern Pacific Ocean. 

Three new species of triplefin blennies of the genus Enneanectes (Teleostei, Tripterygiidae) from the tropical eastern Pacific with a key to Pacific species of Enneanectes.

Three new species of the triplefin blenny genus Enneanectes found in the Pacific Ocean off southern Mexico are described. Two, Enneanectes glendae and Enneanectes macrops, are mainland species, while the third, Enneanectes exsul, is endemic to the Islas Revillagigedo. A key to the five species of Enneanectes known from the tropical eastern Pacific is provided.

Reconciling molecules and morphology: molecular systematics and biogeography of Neotropical blennies (Acanthemblemaria).

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.

Evolution of a Neotropical marine fish lineage (Subfamily Chaenopsinae, Suborder Blennioidei) based on phylogenetic analysis of combined molecular and morphological data.

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.

The Pandemic Blenny, Coralliozetus clausus, a new species of tube blenny endemic to Isla del Coco, Costa Rica (Teleostei: Chaenopsidae).

Coralliozetus clausus, a new species of chaenopsid blenny, endemic to Isla del Coco, Costa Rica, is described. This small species, not exceeding 15 mm SL, is a short-bodied member of the genus along with Coralliozetus cardonae (Caribbean), Coralliozetus angelicus, and Coralliozetus springeri (both eastern Pacific). It differs from its closest relative, C. springeri, known from mainland waters from Costa Rica to Ecuador, in having a single tiny supraorbital cirrus and dark dots on the operculum and branchiostegal membrane of males while C. springeri has paired supraorbital cirri (one of which is substantial in size) and no dots on the operculum. Although two other species of Coralliozetus have been reported from Isla del Coco, this appears to be only member of the genus present on the island. It is the second chaenopsid endemic to Isla del Coco and brings the number of cryptobenthic fishes endemic to Isla del Coco to twelve.

Journey to the West: Trans-Pacific Historical Biogeography of Fringehead Blennies in the Genus Neoclinus (Teleostei: Blenniiformes).

Several temperate marine taxa of the northern hemisphere follow a trans-Pacific biogeographic track with representatives on either side of the intervening boreal waters. Shelter-dwelling blenniiform fishes of the genus Neoclinus exhibit this trans-Pacific distribution pattern with three species in the eastern North Pacific and eight species in the western North Pacific. We reconstructed the phylogeny of the Neocliniini (Neoclinus and the monotypic Mccoskerichthys) using six genetic markers: four mitochondrial genes (COI, cytochrome b, 12S and 16S), and two nuclear genes (RAG-1, TMO-4C4). Ancestral state reconstruction and molecular clock dating were used to explore hypothetical ancestral distributions and area relationships, and to estimate divergent times within this group. The monophyly of the genus Neoclinus, and the reciprocal monophyly of the eastern Pacific and western Pacific lineages were supported. Available evidence, including the eastern Pacific and western Atlantic occurrence of a New World clade of blennioid fishes that includes this lineage, supports the origin of the Neocliniini in the eastern Pacific with a single divergence event to the west across the North Pacific by the ancestor of the western Pacific clade. Estimated divergence time of the eastern and western Pacific clades of Neoclinus was 24.14 million year ago, which falls during the Oligocene epoch. Estimated times of divergence in other trans-Pacific lineages of marine fishes vary widely, from recent Pleistocene events to as early as 34 mya.

Acanthemblemaria aceroi, a new species of tube blenny from the Caribbean coast of South America with notes on Acanthemblemaria johnsoni (Teleostei: Chaenopsidae).

Acanthemblemaria aceroi new species is described from the upwelling region of the Caribbean coasts of Venezuela and Colombia. It differs from its closest relative, Acanthemblemaria rivasi Stephens, 1970, known from Panama and Costa Rica, in the posterior extent of the infraorbitals, details of head spination, and unique COI sequences. The description of Acanthemblemaria johnsonsi Almany Baldwin, 1996, heretofore known only from Tobago, is expanded based on specimens from islands offshore of eastern Venezuela.

A phylogenetic test of the size-advantage model: evolutionary changes in mating behavior influence the loss of sex change in a fish lineage.

The size-advantage model asserts that mating behavior influences the incidence and direction of sex change in animals. Selection for protogyny (female to male sex change) occurs in mating systems in which large males monopolize and pair spawn with females; however, gonochorism (no sex change) is favored when adults spawn in groups and sperm competition is present. Despite widespread empirical and theoretical support for the model, these predictions have not been tested within a phylogenetic context. Here we show that the loss of sex change within a lineage of reef fishes is influenced by evolutionary changes in two traits related to their mating behavior: mating group structure and sperm competition intensity. Phylogenetic reconstructions of the reproductive evolution of groupers (Epinephelidae) indicate that protogyny and paired spawning are the ancestral conditions for the lineage; both gonochorism and group spawning evolved independently at least four times in three different genera. Evolutionary transformations from protogyny to gonochorism (loss of sex change) are associated with equivalent transformations in mating group structure from paired to group spawning, and sperm competition is considerably higher in gonochoric species than in protogynous species. These results provide explicit phylogenetic support for predictions of the size-advantage model, demonstrating that selection for protogynous sex change decreases as mating group size and sperm competition intensity increase.

Evolution of Sexual Dimorphism in Tube Blennies (Teleostei: Chaenopsidae).

The study of sexual differences provides insights into selective factors operating on males and females, especially for clades exhibiting varied levels of dimorphism. Sexual differences in morphology and coloration (melanophores) were compiled for 66 of the 89 species of tube blennies (Blenniiformes, Chaenopsidae) from the systematic literature and examination of preserved specimens. Chaenopsids include essentially monomorphic species and those in which males and females differ in as many as 17 morphological and 14 coloration features. While the sexes of most species differ in coloration (at least at the time of breeding), they are morphologically similar in Acanthemblemaria, Hemiemblemaria, and Lucayablennius. While other genera exhibit an intermediate level of dimorphism, species of Coralliozetus, Cirriemblemaria, and Emblemaria are dramatically dimorphic. Character maps on a phylogenetic hypothesis indicate that this extreme level of dimorphism evolved independently in these genera. A complex history of evolution is implied by examination of jaw length with both increases and decreases in one or both sexes leading to either dimorphism or monomorphism. Several features related to shelter defense are monomorphic in species where both sexes inhabit shelters, but dimorphic where only males occupy shelters. Other dimorphic features increase the conspicuousness of male courtship and aggressive displays.

Evolución del dimorfismo sexual en trambollos tubícolas (Teleostei: Chaenopsidae) (Evolution of sexual dimorphism in tube blennies [Teleostei: Chaenopsidae]) El estudio de las diferencias sexuales proporciona información sobre los factores selectivos que operan en hembras y machos especialmente para clados que muestran niveles variados de dimorfismo. Este estudio se enfocó en las diferencias sexuales en morfología y coloración de 66 especies de blenidos (Blenniiformes, Chaenopsidae). Para lo anterior se analizaron datos provenientes de literatura existente y el análisis de especímenes conservados. Los trambollos tubícolas incluyen especies esencialmente monomórficas y aquellas en las que los machos y las hembras difieren en 17 características morfológicas y 14 de coloración. Si bien los sexos de la mayoría de las especies difieren en la coloración (al menos en el momento de la reproducción), son morfológicamente similares en Acanthemblemaria, Hemiemblemaria, y Lucayablennius. Mientras que otros géneros exhiben un nivel intermedio de dimorfismo, las especies de Coralliozetus, Cirriemblemaria, y Emblemaria poseen un elevado dimorfismo sexual. La hipótesis filogenética indica que este nivel extremo de dimorfismo evolucionó independientemente en estos géneros. Al analizar la longitud de la mandíbula con aumentos y disminuciones en uno o ambos sexos que conducen a dimorfismo o monomorfismo se infiere una compleja historia evolutiva. Varias características relacionadas con la defensa del refugio son monomorfas en especies donde ambos sexos habitan en refugios, pero dimorfa donde solo los machos ocupan refugios. Otras características dimórficas aumentan la visibilidad del cortejo masculino y las exhibiciones agresivas. Translated to Spanish by S. Hinojosa (hinojosa.silvia@gmail.com).

Evolução do dimorfismo sexual em blennies tubulares (Teleostei: Chaenopsidae) (Evolution of sexual dimorphism in tube blennies [Teleostei: Chaenopsidae]) Estudo das diferenças sexuais provém novas idéias sobre fatores seletivos operando em machos e fêmeas, especialmente em clados que exibem níveis variados de dimorfismo. Diferenças sexuais na morfologia e coloração (melanofóros) foram compilados de 66 das 89 espécies de blennies tubulares (Blenniiformes, Chaenopsidae), examinando a literatura em sistemática e espécimes preservados. Chaenopídeos incluem espécies essencialmente monomórficas, além daquelas em que machos e fêmeas diferem em até 17 características morfológicas e 14 de coloração. Embora os sexos da maioria das espécies diferem em coloração (pelo menos no período de reprodução), eles são morfologicamente similares em Acanthemblemaria, Hemiemblemaria, e Lucayablennius. Enquanto outros gêneros exibem níveis intermediários de dimorfismo, espécies de Coralliozetus, Cirriemblemaria, e Emblemaria são dramaticamente dimórficas. Mapeamento de caracteres em uma hipótese filogenética indica que esses níveis extremos de dimorfismo surgiram independentemente nesses gêneros. Uma complexa história de evolução implica o envolvimento do comprimento das mandíbulas, com aumentos e reduções em um ou ambos sexos, levando ao dimorfismo ou monomorfismo. Diversas características relacionadas a defesa das tocas são monomórficas nas espécies em que ambos os sexos habitam tocas; mas nas espécies dimórficas, somente machos ocupam tocas. Outras características dimórficas aumentam a conspicuidade do cortejo masculino e demonstrações de agressividade. Translated to Portuguese by D. Vaz (dbistonvaz@vims.edu).

Fluctuating thermal environments of shallow-water rocky reefs in the Gulf of California, Mexico.

As part of a broad-scale study of the biogeography of rocky reefs in the Gulf of California, Mexico (GOC), we collected a continuous 1-yr temperature time series at ~5 m water depth at 16 sites spanning 5° of latitude and ~700 km along the western boundary of the basin. Throughout the region, thermal conditions were most variable in summer with fluctuations concentrated at diurnal and semi-diurnal frequencies, likely associated with solar and wind forcing and vertical water column oscillations forced by internal waves. Temperatures in winter were less variable than in summer, and minimum temperatures also differed among sites. Thermal variability integrated across the diurnal and semi-diurnal frequency bands was greatest near the Midriff Islands in the northern GOC and decreased toward the southern sites. Diurnal variability was greater than semi-diurnal variability at 13 of the 16 sites. A statistic-of-extremes analysis indicated shortest return times for cooling events in summer, and reef organisms at many of the sites may experience anomalous 2 to 5 °C cooling events multiple times per month. The significant extent of local temperature variability may play important roles in limiting species occurrences among sites across this biogeographic region.