The gustatory stalk of the Remo flounder exemplifies how complex evolutionary novelties may arise.

The appearance of evolutionary novelties is a central issue in biology. Since Darwin's theory, difficulties in explaining how novel intricate body parts arose have often been used by creationists and other deniers to challenge evolution. Here, we describe the gustatory stalk of the Remo flounder (Oncopterus darwinii), an anatomically and functionally complex organ presumably used as a chemoreceptor probe to detect prey buried in the substrate. We demonstrate that the gustatory stalk is derived from the first dorsal-fin ray, which acquired remarkable modifications in its external morphology, integument, skeleton, muscles, and nerves. Such structural innovations are echoed in both functional and ecological specializations. We reveal that the gustatory stalk arose through the gradual accumulation of changes that evolved at different levels of the phylogenetic tree of ray-finned fishes. At least five preconditions arose in nodes preceding Oncopterus darwinii. This finding constitutes an interesting example of how evolution can deeply remodel body parts to perform entirely new functions. In this case, a trivial support structure primitively used for swimming became a sophisticated sensory tool to uncover hidden prey.

A new gelatinous host for pelagic fishes: First in situ record of an association between driftfishes (Stromateiformes, Ariommatidae) and nudibranchs (Mollusca, Phylliroidae).

We describe the first recorded association between fishes and nudibranchs in epipelagic waters. In situ observations and photographs of a juvenile spotted driftfish Ariomma regulus (Stromateiformes; Ariommatidae) swimming alongside the planktonic nudibranch Phylliroe lichtensteinii (Gastropoda; Phylliroidae) were made during blackwater scuba dives off Palm Beach, Florida, United States of America. In this paper, we describe this behavior, highlighting a previously undocumented zooplanktonic host used by fishes. This finding also demonstrates the importance of community science in advancing our understanding of the early life history of marine species.

Facial and opercular muscles in the Anguilliformes (Elopomorpha: Teleostei): Comparative anatomy and phylogenetic implications for the basal position of Protanguilla.

The teleost order Anguilliformes, true eels, comprises more than 1000 described species in 20 families, commonly known as eels, congers, morays, and gulper eels. Comprehensive studies of Anguilliformes are limited, resulting in a lack of consensus for morphology-based phylogenetic hypotheses. A detailed morphological analysis of the cephalic and opercular myology offers a promising new source of characters to help elucidate the intrarelationships of Anguilliformes. Our study is the most extensive myological analysis for the group and includes 97 terminal taxa, with representatives from each of the 20 families of Anguilliformes plus outgroup clades. Results demonstrate that muscle characters inform phylogenetic relationships within Anguilliformes, and we propose two new synapomorphies for all extant members, including Protanguilla palau, the "living fossil"-adductor mandibulae originating on the parietal (vs. restricted to suspensorium) and segmentum mandibularis absent (vs. present). Exceptions for the first condition characterize highly modified saccopharyngoids, and for the second one, Notacanthidae. More importantly, we suggest three new synapomorphies for the remaining extant anguilliforms (except in highly modified saccopharyngoids)-adductor mandibulae originates on the frontals (vs. frontals naked), adductor mandibulae stegalis is separated from the rictalis (vs. ricto-stegalis fused into a single piece), and the levator operculi inserts on the lateral surface of the opercle (vs. medial surface of the opercle). Our phylogenetic optimization strongly corroborates the hypothesis that Protanguilla is the sister group of all other extant eels. A further goal of this paper is to clearly document the substantive conflicts between the available molecular data and the extensive and diverse morphological evidence.

New species of Monomitopus (Ophidiidae) from Hawaii, with the description of a larval coiling behavior.

In 1985, Carter and Cohen noted that there are several yet-to-be described species of Monomitopus (Ophidiidae), including one from Hawaii. Recently, blackwater divers collected a larval fish off Kona, Hawaii, similar to the previously described larvae of M. kumae, but DNA sequence data from the larva does not match any of the six previously sequenced species within the genus. Within the Smithsonian Institutions National Museum of Natural History Ichthyology Collection, we find a single unidentified adult specimen of Monomitopus collected North of Maui, Hawaii in 1972 whose fin-ray and vertebral/myomere counts overlap those of the larval specimen. We describe this new Hawaiian species of Monomitopus based on larval and adult characters. Additionally, blackwater photographs of several species of Monomitopus show the larvae coiled into a tight ball, a novel behavior to be observed in cusk-eels. We describe this behavior, highlighting the importance of blackwater photography in advancing our understanding of marine larval fish biology.

Anatomy and evolution of the pectoral filaments of threadfins (Polynemidae).

The most remarkable anatomical specialization of threadfins (Percomorphacea: Polynemidae) is the division of their pectoral fin into an upper, unmodified fin and a lower portion with rays highly modified into specialized filaments. Such filaments are usually elongate, free from interradial membrane, and move independently from the unmodified fin to explore the environment. The evolution of the pectoral filaments involved several morphological modifications herein detailed for the first time. The posterior articular facet of the coracoid greatly expands anteroventrally during development. Similar expansions occur in pectoral radials 3 and 4, with the former usually acquiring indentations with the surrounding bones and losing association with both rays and filaments. Whereas most percomorphs typically have four or five muscles serving the pectoral fin, adult polynemids have up to 11 independent divisions in the intrinsic pectoral musculature. The main adductor and abductor muscles masses of the pectoral system are completely divided into two muscle segments, each independently serving the pectoral-fin rays (dorsally) and the pectoral filaments (ventrally). Based on the innervation pattern and the discovery of terminal buds in the external surface of the filaments, we demonstrate for the first time that the pectoral filaments of threadfins have both tactile and gustatory functions.

Facial and gill musculature of polynemid fishes, with notes on their possible relationships with sciaenids (Percomorphacea: Perciformes).

The Polynemidae is a family of primarily marine fishes with eight genera and 42 extant species. Many aspects of their morphology are largely unknown, with few reports about their osteology and barely any information on their myology. This paper describes and illustrates in detail all facial and branchial muscles of representative species of polynemids. Our analysis demonstrates the existence of several remarkable and previously unknown specializations in the polynemid musculature. The aponeurotic and completely independent origin of the pars promalaris of the adductor mandibulae is apparently unique among percomorphs. The differentiation of this section into lateral and medial subsections; the total separation of the promalaris from the retromalaris; the differentiation of the pars primordialis of the levator arcus palatini into external and internal subsections are also uncommon features of polynemids that are shared by sciaenids, thus supporting the hypothesis of a closer relationship between these families.

Phylogenetic interrelationships of the eel families Derichthyidae and Colocongridae (Elopomorpha: Anguilliformes) based on the pectoral skeleton.

A cladistic analysis of the eel families Derichthyidae and Colocongridae is herein proposed for the first time on the basis of morphological data. We discovered dozens of new phylogenetic characters derived from a detailed analysis of the pectoral skeleton, an anatomical system neglected by most previous studies. Our maximum parsimony analysis indicates that Colocongridae sensu lato is paraphyletic, with its two constituent genera Coloconger and Congriscus appearing as successive sister groups of derichthyids. Monophyly of the family Derichthyidae, which has been questioned by some studies, is herein strongly supported by 10 unambiguous synapomorphies. We also stress the importance of the appendicular skeleton as a useful source of phylogenetic information for the resolution of systematic problems within Anguilliformes.

Reconsidering pectoral girdle and fin morphology in Anguillidae (Elopomorpha: Anguilliformes).

The morphology of the pectoral girdle and fin of Anguillidae is reconsidered via the inclusion of skeletal components that have previously been unassessed. For example, the pectoral girdle and fin in Anguilla were erroneously reported to lack a scapular bone, a cartilaginous scapulocoracoid plate and a cartilaginous propterygium. The pectoral morphology of Anguilla is also compared with the closely related genus Nemichthys, including additional data on the anatomy of this eel family.

Two new species of callanthiid fishes of the genus Grammatonotus (Percoidei: Callanthiidae) from Pohnpei, western Pacific.

In late July/early August 2015, ichthyologists from the Bishop Museum collecting fishes off Pohnpei in the Caroline Islands group, western Pacific Ocean, obtained specimens of two undescribed species of Grammatonotus. One of the new species, G. xanthostigma, closely resembles the recently described G. brianne, differing most strikingly in the shape of the caudal fin. The other, G. pelipel, is distinctive in having the following combination of characters: disjunct lateral line, barred pattern of coloration (most distinctive in small individuals), and caudal fin truncate to slightly emarginate in small specimens, but with upper and lower lobes produced in largest example known. Herein we provide characters that distinguish callanthiids from other percoids and that distinguish Grammatonotus from Callanthias, the other genus in the family Callanthiidae, along with descriptions of the new species.

Evolution of a Functional Head Joint in Deep-Sea Fishes (Stomiidae).

The head and anterior trunk region of most actinopterygian fishes is stiffened as, uniquely within vertebrates, the pectoral girdles have a direct and often strong connection through the posttemporal to the posterior region of the skull. Members of the mesopelagic fish family Stomiidae have their pectoral girdle separated from the skull. This connection is lost in several teleost groups, but the stomiids have an additional evolutionary novelty-a flexible connection between the occiput and the first vertebra, where only the notochord persists. Several studies suggested that stomiids engulf significantly large prey items and conjectured about the functional role of the anterior part of the vertebral column; however, there has been no precise anatomical description of this complex. Here we describe a unique configuration comprising the occiput and the notochordal sheath in Aristostomias, Eustomias, Malacosteus, Pachystomias, and Photostomias that represents a true functional head joint in teleosts and discuss its potential phylogenetic implications. In these genera, the chordal sheath is folded inward ventrally beneath its connection to the basioccipital and embraces the occipital condyle when in a resting position. In the resting position (wherein the head is not manipulatively elevated), this condyle is completely embraced by the ventral fold of the notochord. A manual manipulative elevation of the head in cleared and stained specimens unfolds the ventral sheath of the notochord. As a consequence, the cranium can be pulled up and back significantly farther than in all other teleost taxa that lack such a functional head joint and thereby can reach mouth gapes up to 120°.

A new genus and species of the family Symphysanodontidae, Cymatognathus aureolateralis (Actinopterygii: Perciformes) from Indonesia.

A new genus and species of the percoid family Symphysanodontidae, Cymatognathus aureolateralis are described based on three specimens collected from North Sulawesi, Indonesia. The new species shares with the confamilial genus Sym-physanodon the unique supraneural and spinous dorsal-fin pterygiophore insertion pattern usually of 0/0/0+2+1/1/, T-shaped first supraneural, foreshortened base of the penultimate ventral procurrent caudal-fin ray, well-developed outer tooth patches at anterior tips of both jaws as well as along the medial surface of most of the length of the coronoid process of the dentary. The new species, however, is distinguishable from members of Symphysanodon by the following diagnostic characters: posterior tip of coronoid process of dentary abruptly depressed, so that teeth on anterior portion appear as an elevated patch, anterior tip of upper jaw not notched, and posterior nostril horizontally slit-like. Although the new species superficially resembles the members of the genus Giganthias (Giganthiidae) and some members of the subfamily Anthiadinae (Serranidae) in the unique characters it shares with Symphysanodon, it differs from Giganthias in having the above-mentioned unique pterygiophore insertion pattern and tips of all dorsal- and pelvic-fin spines smooth (vs. pterygiophore insertion pattern 0/0/2/1+1/1/, and tips of second, third and/or fourth dorsal- and pelvic-fin spines serrated), and from the members of Anthiadinae in having two flat opercular spines (vs. three) and 10 + 15 = 25 vertebrae (vs. 10 + 16-18 = 26-28). A revised diagnosis of the Symphysanodontidae is presented.

Hidden diversity in deep-water bandfishes: review of Owstonia with descriptions of twenty-one new species (Teleostei: Cepolidae: Owstoniinae).

The bandfish family Cepolidae, comprising the subfamilies Owstoniinae and Cepolinae, is characterized, and defining characters of the three groups are identified and discussed. Characters of larvae of both subfamilies are described and illustrated. Six nominal genera of owstoniines had been proposed by various authors, but we recognize only Owstonia Tanaka. Utility of selected identification characters of the genus are discussed. Differences in lateral-line patterns have been the primary character used by some recent authors for recognition of two owstoniine genera, with Sphenanthias Weber possessing the plesiomorphic lateral-line condition. Several other patterns also occur in these fishes bringing into question the phylogenetic significance of lateral line plasticity. Sexual dimorphism in pelvic fin lengths is also present in several species. Identification keys, descriptions, synonymies, distribution maps and photographs or illustrations are provided for all Owstonia species for which adults are available.        Although only 15 valid species were previously known, a remarkable hidden diversity of these fishes was discovered in major museum collections with the following 21 species here described as new: O. ainonaka (eastern Australia), O. contodon (Philippines), O. crassa (New Caledonia and Solomon Islands), O. dispar (Solomon Islands), O. elongata (New Caledonia and Vanuatu), O. fallax (eastern Australia and New Caledonia), O. geminata (Vanuatu and Philippines), O. hastata (eastern Australia), O. hawaiiensis (Hawaiian Islands); O. ignota (Mariana Islands), O. lepiota (Tanzania), O. melanoptera (Philippines), O. merensis (eastern Australia, Torres Strait), O. mundyi (Kiribati, Christmas Island), O. nalani (eastern Australia and New Caledonia), O. nudibucca (eastern Indian Ocean, Mentawai Islands and off Myanmar), O. psilos (Western Australia), O. raredonae (Mozambique), O. rhamma (Vanuatu), O. scottensis (Western Australia, Scott Reefs) and O. similis (Madagascar). Several specimens based on small juveniles, which we describe as Owstonia sp.,  appear to be additional new species but are not formally described as such.

Validation of the synonymy of the teleost blenniid fish species Salarias phantasticus Boulenger 1897 and Salarias anomalus Regan 1905 with Ecsenius pulcher (Murray 1887) based on DNA barcoding and morphology.

As currently recognized, Ecsenius pulcher includes Salarias pulcher (type material has a banded color pattern), S. anomalus (non-banded), and S. phantasticus (banded). The color patterns are not sex linked, and no other morphological features apparently distinguish the three nominal species. The recent collection of banded and non-banded specimens of Ecsenius pulcher from Iran has provided the first tissue samples for genetic analyses. Here we review the taxonomic history of E. pulcher and its included synonyms and genetically analyze tissue samples of both color patterns. Salarias anomalus is retained as a synonym of E. pulcher because DNA barcode data suggest that they represent banded and non-banded color morphs of a single species. Furthermore, the large size of the largest type specimen of S. anomalus (herein designated as the lectotype) suggests that it belongs to E. pulcher. A single non-banded specimen from Iran is genetically distinct from E. pulcher and appears to represent an undescribed species. Salarias phantasticus is retained as a synonym of E. pulcher because the primary morphological difference between the two nominal species-presence of spots on the dorsal fin in E. pulcher and absence of those spots in S. phantasticus-is not a valid taxonomic character; rather, the spots represent galls that contain the larval stages of a parasitic crustacean. As males and females of Ecsenius species have been confused in the literature, we describe and illustrate the genital regions of both and comment on possible new blenniid synapomorphies that our investigation revealed.

The infrabranchial musculature and its bearing on the phylogeny of percomorph fishes (Osteichthyes: Teleostei).

The muscles serving the ventral portion of the gill arches ( = infrabranchial musculature) are poorly known in bony fishes. A comparative analysis of the infrabranchial muscles in the major percomorph lineages reveals a large amount of phylogenetically-relevant information. Characters derived from this anatomical system are identified and discussed in light of current hypotheses of phylogenetic relationships among percomorphs. New evidence supports a sister-group relationship between the Batrachoidiformes and Lophiiformes and between the Callionymoidei and Gobiesocoidei. Investigated data also corroborate the existence of two monophyletic groups, one including the Pristolepididae, Badidae, and Nandidae, and a second clade consisting of all non-amarsipid stromateiforms. New synapomorphies are proposed for the Atherinomorphae, Blenniiformes, Lophiiformes, Scombroidei (including Sphyraenidae), and Gobiiformes. Within the latter order, the Rhyacichthyidae and Odontobutidae are supported as the successive sister families of all remaining gobiiforms. The present analysis further confirms the validity of infrabranchial musculature characters previously proposed to support the grouping of the Mugiliformes with the Atherinomorphae and the monophyly of the Labriformes with the possible inclusion of the Pholidichthyiformes. Interestingly, most hypotheses of relationships supported by the infrabranchial musculature have been advanced by preceding anatomists on the basis of distinct data sources, but were never recovered in recent molecular phylogenies. These conflicts clearly indicate the current unsatisfactory resolution of the higher-level phylogeny of percomorphs.

Connectivity across the Caribbean Sea: DNA barcoding and morphology unite an enigmatic fish larva from the Florida straits with a new species of sea bass from deep reefs off Curaçao.

Integrative taxonomy, in which multiple disciplines are combined to address questions related to biological species diversity, is a valuable tool for identifying pelagic marine fish larvae and recognizing the existence of new fish species. Here we combine data from DNA barcoding, comparative morphology, and analysis of color patterns to identify an unusual fish larva from the Florida Straits and demonstrate that it is the pelagic larval phase of a previously undescribed species of Liopropoma sea bass from deep reefs off Curaçao, southern Caribbean. The larva is unique among larvae of the teleost family Serranidae, Tribe Liopropomini, in having seven elongate dorsal-fin spines. Adults of the new species are similar to the golden bass, Liopropoma aberrans, with which they have been confused, but they are distinct genetically and morphologically. The new species differs from all other western Atlantic liopropomins in having IX, 11 dorsal-fin rays and in having a unique color pattern-most notably the predominance of yellow pigment on the dorsal portion of the trunk, a pale to white body ventrally, and yellow spots scattered across both the dorsal and ventral portions of the trunk. Exploration of deep reefs to 300 m using a manned submersible off Curaçao is resulting in the discovery of numerous new fish species, improving our genetic databases, and greatly enhancing our understanding of deep-reef fish diversity in the southern Caribbean. Oh the mother and child reunion is only a moment away. Paul Simon.

Ontogeny and homology of the skeletal elements that form the sucking disc of remoras (Teleostei, Echeneoidei, Echeneidae).

The sucking disc of the sharksuckers of the family Echeneidae is one of the most remarkable and most highly modified skeletal structures among vertebrates. We studied the development of the sucking disc based on a series of larval, juvenile, and adult echeneids ranging from 9.3 mm to 175 mm standard length. We revisited the question of the homology of the different skeletal parts that form the disc using an ontogenetic approach. We compared the initial stages of development of the disc with early developmental stages of the spinous dorsal fin in a representative of the morphologically basal percomorph Morone. We demonstrate that the "interneural rays" of echeneids are homologous with the proximal-middle radials of Morone and other teleosts and that the "intercalary bones" of sharksuckers are homologous with the distal radials of Morone and other teleosts. The "intercalary bones" or distal radials develop a pair of large wing-like lateral extensions in echeneids, not present in this form in any other teleost. Finally the "pectinated lamellae" are homologous with the fin spines of Morone and other acanthomorphs. The main part of each pectinated lamella is formed by bilateral extensions of the base of the fin spine just above its proximal tip, each of which develops a row of spinous projections, or spinules, along its posterior margin. The number of rows and the number of spinules increase with size, and they become autogenous from the body of the lamellae. We also provide a historical review of previous studies on the homology of the echeneid sucking disc and demonstrate that the most recent hypotheses, published in 2002, 2005 and 2006, are erroneous.

A 'living fossil' eel (Anguilliformes: Protanguillidae, fam. nov.) from an undersea cave in Palau.

We report the discovery of an enigmatic, small eel-like fish from a 35 m-deep fringing-reef cave in the western Pacific Ocean Republic of Palau that exhibits an unusual suite of morphological characters. Many of these uniquely characterize the Recent members of the 19 families comprising the elopomorph order Anguilliformes, the true eels. Others are found among anguilliforms only in the Cretaceous fossils, and still others are primitive with respect to both Recent and fossil eels. Thus, morphological evidence explicitly places it as the most basal lineage (i.e. the sister group of extant anguilliforms). Phylogenetic analysis and divergence time estimation based on whole mitogenome sequences from various actinopterygians, including representatives of all eel families, demonstrate that this fish represents one of the most basal, independent lineages of the true eels, with a long evolutionary history comparable to that of the entire Anguilliformes (approx. 200 Myr). Such a long, independent evolutionary history dating back to the early Mesozoic and a retention of primitive morphological features (e.g. the presence of a premaxilla, metapterygoid, free symplectic, gill rakers, pseudobranch and distinct caudal fin rays) warrant recognition of this species as a 'living fossil' of the true eels, herein described as Protanguilla palau genus et species nov. in the new family Protanguillidae.

Influenza vaccination acceptance and refusal rates among health care personnel.

OBJECTIVES: The primary aim of this study was to determine reasons why health care personnel (HCP) in a public health department chose or refused free influenza vaccinations offered at the worksite. METHODS: In an internal review board-approved study, we offered, through a health nurse at the site, self-administered surveys designed to evaluate HCPs' reasons for choosing or refusing influenza vaccination, HCP knowledge of vaccination recommendations, and other items such as demographic information. We tested for differences between the vaccinated and non-vaccinated cohorts, and conducted multiple logistic regression analysis to identify likely predictors of future vaccine acceptance. RESULTS: Predictors of vaccine noncompliance were fear of needles (P ≤ 0.042), fear of getting sick from the vaccine (P ≤ 0.000), disbelief that the vaccine is effective (P ≤ 0.000), ignoring vaccination as a healthy behavior (P ≤ 0.000), and younger age (P ≤ 0.026). Nonvaccinated HCP were less likely than vaccinated HCP to report. Vaccines are encouraged because of (a) minimizing sick days and loss of productivity (P ≤ 0.000); (b) sick patients are exposed to influenza by HCP (P ≤ 0.000); or (c) note any reason (P ≤ 0.006). CONCLUSION: The non-vaccinated group refused the vaccine primarily for reasons related to misconceptions regarding the effectiveness and health risks of the vaccine, as well as a belief that the vaccine is unnecessary. Conversely, the vaccinated cohort chose the vaccine for the primary reasons that the vaccine is effective, a vaccine is demonstrative of healthy behavior choices, and influenza is transmitted both to and from sick patients.

New insights into the complex structure and ontogeny of the occipito-vertebral gap in barbeled dragonfishes (Stomiidae, Teleostei).

In all stomiid genera there is an occipito-vertebral gap between the skull and the first vertebra bridged only by the flexible notochord. Morphological studies from the early 20th century suggested that some stomiid genera have 1-10 of the anteriormost centra reduced or entire vertebrae missing in this region. Our study reviews this previous hypothesis. Using a new approach, we show that only in Chauliodus, Eustomias and Leptostomias gladiator vertebral centra are actually lost, with their respective neural arches and parapophyses persisting. We present results from a comparative analysis of the number and insertion sites of the anteriormost myosepta in 26 of the 28 stomiid genera. Generally in teleosts the first three myosepta are associated with the occiput, and the fourth is the first vertebral myoseptum. The insertion site of the fourth myoseptum plays an important role in this analysis, because it provides a landmark for the first vertebra. Lack of association of the fourth myoseptum with a vertebra is thus evidence that the first vertebra is reduced or absent. By counting the occipital and vertebral myosepta the number of reduced vertebrae in Chauliodus, Eustomias and Leptostomias gladiator can be inferred. Proper identification of the spino-occipital nerves provides an additional source of information about vertebral reduction. In all other stomiid genera the extensive occipito- vertebral gap is not a consequence of the reduction of vertebrae, but of an elongation of the notochord. The complex structure and ontogeny of the anterior part of the vertebral column of stomiids are discussed comparatively.

Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families.

The oceanic bathypelagic realm (1000-4000 m) is a nutrient-poor habitat. Most fishes living there have pelagic larvae using the rich waters of the upper 200 m. Morphological and behavioural specializations necessary to occupy such contrasting environments have resulted in remarkable developmental changes and life-history strategies. We resolve a long-standing biological and taxonomic conundrum by documenting the most extreme example of ontogenetic metamorphoses and sexual dimorphism in vertebrates. Based on morphology and mitogenomic sequence data, we show that fishes currently assigned to three families with greatly differing morphologies, Mirapinnidae (tapetails), Megalomycteridae (bignose fishes) and Cetomimidae (whalefishes), are larvae, males and females, respectively, of a single family Cetomimidae. Morphological transformations involve dramatic changes in the skeleton, most spectacularly in the head, and are correlated with distinctly different feeding mechanisms. Larvae have small, upturned mouths and gorge on copepods. Females have huge gapes with long, horizontal jaws and specialized gill arches allowing them to capture larger prey. Males cease feeding, lose their stomach and oesophagus, and apparently convert the energy from the bolus of copepods found in all transforming males to a massive liver that supports them throughout adult life.