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Figure 2 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 2. †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. A, B, MGP-PD 26275/6, holotype in part and counterpart. Scale bars = 100 mm.

Figure 8 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 8. Visual image of the principal component analysis (PCA) performed on the entire set of log-transformed standardized morphometric and meristic features, showing the separation of the specimens referred to †Titanonarke molini (right side of morphospace) from those referred to †Titanonarke megapterygia sp. nov. (left side). The illustrations lying along the extreme values of PC1 represent the hypothetical reconstruction of the two species based on body proportions.

Figure 11 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 11. Pelvic fins of †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. A, MCSNV IG.VR.67290; B, reconstruction. Abbreviations: bas, basipterygia; ilp, iliac process; pel, pelvic processes; pub, puboischiadic bar; rad, pelvic radials. The arrowhead indicates the iliac process. Scale bars = 50 mm.

Figure 7 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 7. †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. A, B, UV images of the holotype MGP-PD 26275/6 showing that it was covered with a pigment reflecting an orange light (see also Supplementary material). The arrows in A indicate a leaf also covered with the pigment, a drop, and some rays that were not distally covered (they are blue/grey, as expected); the arrowhead in A indicates part of the third branch of the antorbital cartilage not covered by pigment; the arrowhead in B indicates the rostral appendix; C, Narcine brasiliensis (TNHC 18512); the arrows indicate the rostral appendices. Scale bars: A, B = 50 mm; C = 10 mm.

Figure 5 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 5. †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. A, MCSNV IG.VR.67290, close-up of the head and hyoid apparatus; B, reconstruction. Abbreviations: ao, antorbital cartilage; bb, basibranchials; bbc, basibranchial copula; cb, ceratobranchials; cc, chondrocranium; eb, epibranchials; hb, hypobranchials; hym, hyomandibula; la, labial cartilages; me, Meckel's cartilage; nc, nasal capsule; pq, palatoquadrate; ps, pseudohyoid; ra, rostral appendix; rf, rostral fontanelle; ro, rostral cartilage; sca, scapulocoracoid; ss, suprascapula; syn, synarcual. Scale bars = 50 mm.

Figure 10 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 10. Pectoral fin of †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. A, MCSNV IG.VR.67290; B, reconstruction; different colours are used to distinguish the propterygial (green), mesopterygial (yellow) and metapterygial (red) radials (colours in the online version). Abbreviations: mes, mesopterygium; met, metapterygium; pro, propterygium; sca, scapulocoracoid. Scale bars = 50 mm.

Figure 18 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 18. The single tree retrieved in TNT 1.5 based on 72 morphological characters and 16 taxa, showing the hypothetic relationships of †Titanonarke and †Eotorpedo within the Torpediniformes. Black squares indicate consistency index (CI) = 1.00; white squares CI <1.00.

Figure 14 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 14. †Titanonarke molini (Jaekel, 1894) from the Eocene of Monte Postale site. A, upper and lower tooth bands in MCSNV IG.VR.67290, with a close-up of some teeth in the area indicated. B, reconstruction. Abbreviations: la, labial cartilage; me, Meckel's cartilage; pq, palatoquadrate. Scale bars 5 mm.

Figure 13 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 13. †Titanonarke molini (Jaekel, 1894) from the Eocene Monte Postale site. Details of the precaudal tail of A, MCSNV IG. VR.67290 and B, MGP-PD 26276. The arrows mark the position of the two dorsal fins in MCSNV IG.VR.67290 and the second dorsal fin in MGP-PD 26276 already detected and figured by Jaekel (1894). C, Detail of the caudal fin of MCSNV IG.91129. Scale bars: A, B = 50 mm; C = 10 mm.

Figure 19 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Figure 19. Palaeobiogeographical distribution of the Torpediniformes during the Cenozoic: 1, Texas; 2, Belgium; 3, Morocco; 4, Jordan; 5, Saudi Arabia; 6, Enclave of Cabinda; 7, Nigeria; 8, Niger; 9, Cameroun; 10, Senegal; 11, Tunisia; 12, South Carolina; 13, France; 14, Guinea-Bissau; 15, Togo; 16, Egypt; 17, Italy; 18, Portugal; 19, Switzerland; 20, Germany; 21, Netherlands. Data from Hasse (1879), Jaekel (1904), White (1934), Dartvelle & Casier (1943), Arambourg (1952), Cappetta et al. (1967, 2000), Cappetta (1972, 1987, 1988, 2012), Herman (1974), Banks (1978), Cappetta & Traverse (1988), Cappetta & Nolf (1991), Bolliger et al. (1995), Madden et al. (1995), Noubhani & Cappetta (1997), Antunes et al. (1999), Smith (1999), Bracher (2005), Reinecke et al. (2005), Adnet (2006), Knight et al. (2007), Adnet et al. (2010), Carvalho (2010), Mollen (2010), Underwood et al. (2011), Case et al. (2015), Reinecke (2015) and Siguendibo Sambou et al. (2017). Maps are modified from Scotese (2002).

opennotspecifiedOct 2019View details →

Figure 3 in A new subfamily for a clade of opecoelids (Trematoda: Digenea) exploiting marine fishes as second-intermediate hosts, with the first report of opecoelid metacercariae from an elasmobranch

Figure 3. The pylogenetic pattern of second-intermediate host groups, including Amphipoda, Cephalopoda, Chondricthyes, Decapoda, Echinoidea, Gastropoda, Hirudinea, Insecta, Oligochaeta and Osteichthyes, exploited by the Opecoelidae, constructed through maximum likelihood analysis of partial 28S ribosomal DNA data, with two brachycladioids forming the outgroup. Taxa in collapsed clades and GenBank accession numbers for all taxa are listed in Table 3. New sequence data are in bold. Support values <50% are omitted. Scale bar indicates the number of substitutions per site.

opencc-zeroFeb 2022View details →

A national scale BioBlitz using citizen science and eDNA metabarcoding for monitoring coastal marine fish

Marine biodiversity is threatened by human activities. To understand the changes happening in aquatic ecosystems and to inform management, detailed, synoptic monitoring of biodiversity across large spatial extents is needed. Such monitoring is challenging due to the time, cost, and specialized skills that this typically requires. In an unprecedented study, we here combined citizen science with eDNA metabarcoding to map coastal fish biodiversity at a national scale. We engaged 360 citizen scientists to collect filtered sea water samples from 100 sites across Denmark over two seasons (1 pm on September 29th 2019 and May 10th 2020), and by sampling at nearly the exact same time across all 100 sites, we obtained an overview of fish biodiversity largely unaffected by temporal variation. This would have been logistically impossible for the involved scientists without the help of volunteer citizens. We obtained a high return rate of 94% of the samples, and a total richness of 52 fish species, representing approximately 80% of coastal Danish fish species and approximately 25% of all Danish marine fish species. We retrieved distribution patterns matching known occurrence for both invasive, endangered, and cryptic species, and detected seasonal variation in accordance with known phenology. Dissimilarity of eDNA community compositions increased with distance between sites. Importantly, comparing our eDNA data with National Fish Atlas data (the latter compiled from a century of observations) we found positive correlation between species richness values and a congruent patterns of community compositions. These findings support the use of eDNA-based citizen science to detect patterns in biodiversity, and our approach is readily scalable to other countries, or even regional and global scales. We argue that future large-scale biomonitoring will benefit from using citizen science combined with emerging eDNA technology, and that such an approach will be important for data-driven biodiversity management and conservation.

opencc-zeroJun 2022View details →

Fishing, predation, and temperature drive herring decline in a large marine ecosystem

Since 1960, landings of Atlantic herring have been the greatest of any marine species in Canada, surpassing Atlantic cod and accounting for 24% of the total seafood harvested in Atlantic Canada. The Scotian Shelf-Bay of Fundy herring fisheries (NAFO Division 4VWX) is among Canada's oldest and drives this productivity, accounting for up to 75% of the total herring catch in some years. The stocks' productivity and overall health have declined since 1965. Despite management measures to promote recovery implemented since 2003, biomass remains low and is declining. The factors that drive the productivity of 4VWX herring are primarily unresolved, likely impeding the effectiveness of management actions on this stock. We evaluated potential drivers of herring variability by analyzing 52 time-series that describe the temporal and spatial evolution of the 4VWX herring population and the physical, ecological, and anthropogenic factors that could affect them using structural equation models. Variation in herring biomass was best accounted for by the exploitation rate's negative effect and the geographic distribution of fishing and recruitment. Thermal phenology and temperature adversely and egg predation positively impacted the early life stage mortality rate and, ultimately, adult biomass. These findings are broadly relevant to fisheries management, but particularly for 4VWX herring, where the current management approach does not consider their early life stage dynamics or assess them within the ecosystem or climate change contexts.

FIGURE 1 in Enenterum kyphosi Yamaguti, 1970 and Enenterum petrae n. sp. (Digenea Enenteridae) from kyphosid fishes (Centrarchiformes: Kyphosidae) collected in marine waters off eastern Australia

FIGURE 1. Bayesian majority-rule consensus tree of the 28S rDNA alignment. Bayesian inference (BI) posterior probabilities (pp) for nodes represented by circles, maximum likelihood (ML) bootstrap support (bs) represented by squares. Support values less than 0.90 (pp) and 70 (bs) not shown. The scale-bar indicates the number of substitutions per site. GenBank accession number for each sequence presented under taxa name.

FIGURE 3. Enenterum kyphosi Yamaguti, 1970, scanning electron micrographs. a, b, c in Enenterum kyphosi Yamaguti, 1970 and Enenterum petrae n. sp. (Digenea Enenteridae) from kyphosid fishes (Centrarchiformes: Kyphosidae) collected in marine waters off eastern Australia

FIGURE 3. Enenterum kyphosi Yamaguti, 1970, scanning electron micrographs. a, b, c. oral suckers of adult whole specimens ex Kyphosus cinerascens from Amity Point, Queensland, Australia. d. tegument of worm shown in frame b. showing spines. Scale bars: a, c. 200 µm; b. 100 µm; d. 20 µm. Abbreviations: Cc, central cleft; Ds, dorsal section; Nds, notch in dorsal lobe; Ls, lateral section; Pp, papilla; Sc, sagittal cleft; Vs, ventral section.

FIGURE 4. Enenterum petrae n in Enenterum kyphosi Yamaguti, 1970 and Enenterum petrae n. sp. (Digenea Enenteridae) from kyphosid fishes (Centrarchiformes: Kyphosidae) collected in marine waters off eastern Australia

FIGURE 4. Enenterum petrae n. sp. a. holotype, ventral view. b. cirrus-sac of paratype, lateral view. c. paratype, lateral view. Scale bars: a, c. 1,000 µm; b. 500 µm. Abbreviations: An, anus; As, accessory sucker; Cs, cirrus sac; E, egg; Ep, excretory pore; Ev, excretory vesicle; Ga, genital atrium; Gc, genital cap; Gp, genital pore; Int, intestine; Mg, Mehlis' gland; O, ovary; Oes, oesophagus; Os, oral sucker; Ph, pharynx; PPh, prepharynx; Pp, pars prostatica; Sr, seminal receptacle; T, testis; U, uterus; Vd, vasa deferentia; Vf, vitelline follicle; Vs, ventral sucker.

FIGURE 2. Enenterum kyphosi Yamaguti, 1970. a. holotype, ventral view. b in Enenterum kyphosi Yamaguti, 1970 and Enenterum petrae n. sp. (Digenea Enenteridae) from kyphosid fishes (Centrarchiformes: Kyphosidae) collected in marine waters off eastern Australia

FIGURE 2. Enenterum kyphosi Yamaguti, 1970. a. holotype, ventral view. b. cirrus-sac of paratype, ventral view. Scale bars: a. 1,000 µm; b. 500 µm. Abbreviations: An, anus; Cs, cirrus sac; E, egg; Ep, excretory pore; Ev, excretory vesicle; Ga, genital atrium; Gp, genital pore; Gpa, genital papilla; Int, intestine; Mg, Mehlis' gland; O, ovary; Oes, oesophagus; Os, oral sucker; Ph, pharynx; PPh, prepharynx; Pp, pars prostatica; Sr, seminal receptacle; T, testis; U, uterus; Vd, vasa deferentia; Vf, vitelline follicle; Vs, ventral sucker.

opencc-zeroJun 2022View details →

Genetic structure and dispersal in peripheral populations of a marine fish (Pacific cod, Gadus macrocephalus) and their importance for adaptation to climate change

Small and isolated peripheral populations, which are often remnants of glacial refugia, offer an opportunity to determine the magnitude and direction of fine-scale connectivity in high gene flow marine species. When located at the equatorial edge of a species' range, these populations may also harbor genetic diversity related to survival and reproduction at higher temperatures, a critical resource for marine species facing warming ocean temperatures. Pacific cod (Gadus macrocephalus), a marine fish in the North Pacific, has already experienced major shifts in biomass and distribution linked to climate change. We estimated the magnitude and direction of connectivity between peripheral populations of Pacific cod at the southern edge of the species' range, by conducting restriction site-associated DNA (RAD) sequencing and individual assignment on fish collected around the Korean Peninsula during the spawning season. Three populations on the western, eastern, and southern Korean coasts were highly differentiated (FST =0.025 – 0.042) and relatively small (Ne = 433-1777). Ten putative dispersers and estimates of contemporary migration rates revealed asymmetrical, west-to-east movement around the Korean Peninsula, at a higher rate than predicted by indirect estimates of connectivity (FST). Allele frequencies at 87 RAD loci were decisively correlated with strong marine temperature gradients between the warmer southern coast and the cooler waters of the eastern and western coasts. Despite relatively small sample sizes, our data suggest asymmetrical dispersal and gene flow, potentially involving adaptive alleles, between peripheral populations inhabiting markedly different thermal regimes. Our study emphasizes the conservation value of peripheral populations in high gene flow marine fish species.

opencc-zeroDec 2016View details →

Data from: Extraordinarily rapid speciation in a marine fish

Divergent selection may initiate ecological speciation extremely rapidly. How often and at what pace ecological speciation proceeds to yield strong reproductive isolation is more uncertain. Here, we document a case of extraordinarily rapid speciation associated with ecological selection in the postglacial Baltic Sea. European flounders (Platichthys flesus) in the Baltic exhibit two contrasting reproductive behaviors: pelagic and demersal spawning. Demersal spawning enables flounders to thrive in the low salinity of the Northern Baltic, where eggs cannot achieve neutral buoyancy. We show that demersal and pelagic flounders are a species pair arising from a recent event of speciation. Despite having a parapatric distribution with extensive overlap, the two species are reciprocally monophyletic and show strongly bimodal genotypic clustering and no evidence of contemporary migration, suggesting strong reproductive isolation. Divergence across the genome is weak but shows strong signatures of selection, a pattern suggestive of a recent ecological speciation event. We propose that spawning behavior in Baltic flounders is the trait under ecologically based selection causing reproductive isolation, directly implicating a process of ecological speciation. We evaluated different possible evolutionary scenarios under the approximate Bayesian computation framework and estimate that the speciation process started in allopatry ∼2,400 generations ago, following the colonization of the Baltic by the demersal lineage. This is faster than most known cases of ecological speciation and represents the most rapid event of speciation ever reported for any marine vertebrate.