Find research datasets worth reusing

Fig. 1 in Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

Fig. 1. Mean (± S.E.M) bimonthly variations of the gonadosomatic index in Metynnis maculatus females (n = 36). The different letters indicate significant differences among months. (ANOVA, Tukey test, P <0.05).

Fig. 5 in Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

Fig. 5. (a) Pearson correlation between the volume density of final vitellogenic oocytes and the gonadosomatic index (GSI) (%) during the reproductive cycle of Metynnis maculatus females (n = 36). (b) Pearson correlation between the volume density of post-ovulatory follicles and the GSI (%) (n = 36). (c) Pearson correlation between the E 2 plasma levels and the GSI (%) (n = 20). (d) Pearson correlation between the 17α-OHP plasma levels and the GSI (%) (n = 20). (e) Pearson correlation between the E 2 plasma levels and the volume density of final vitellogenic oocytes (n = 20). (f) Pearson correlation between the 17α-OHP plasma levels and the volume density of the post-ovulatory follicles (n = 20). The continuous line indicates that the difference is statistically significant (Pearson's test, P <0.05).

Fig. 4 in Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

Fig. 4. (a) Mean (± S.E.M) bimonthly plasma concentrations of E 2 in Metynnis maculatus females (n = 20). Different letters indicate significant differences among months (ANOVA, Tukey test, P <0.05). (b) Mean (± S.E.M) bimonthly plasma 17α – OHP concentrations (n = 20). Different letters indicate significant differences among months. (ANOVA, Tukey test, P <0.05).

Fig. 3 in Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

Fig. 3. Mean percentages (± S.E.M) of different oocyte types from Metynnis maculatus females during the ovarian maturation cycle. Different letters indicate significant differences among the same type of oocytes among months (ANOVA, Tukey test, P <0.05).

Fig. 2 in Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

Fig. 2. Photomicrographs of different oocyte types observed during the Metynnis maculatus reproductive cycle. (a) Previtellogenic oocytes showing multiple nucleolus (arrow), (b) Cortical alveoli oocyte; (c) Early vitellogenic oocyte with cytoplasm filled mostly with cortical alveoli (asterisk); (d) Final vitellogenic oocyte with cytoplasm completely filled with protein yolk granules (asterisk); (e) Post ovulatory follicles with numerous border folding (arrow), (f) Atretic oocytes with fragmented vitelline membrane (arrow) and a change in the appearance of the cytoplasm (asterisk). Hematoxylin-floxin. Scale bar = 100 µM..

opencc-by-4.0Dec 2023View details →

Figure 1 in Testing predictions of length at first maturity of teleostean fishes, given their maximum length

Figure 1. – Schematic representation of how, in fish, a declining relative gill surface area (G-lines in A-D) and thus oxygen (O2) supply imposes a limit to body weight (Wmax) when the oxygen reaches a level just sufficient for maintenance (Qmaint in A). When a stress factor (e.g., a higher temperature) increases the O2 demand for maintenance, Wmax is reached at smaller sizes (B). Maturation and spawning must occur at a size Wm Qmaint (C). This contribution suggests that the ratio Qm/ Qmaint is similar and constant among fishes, thus enabling them to adjust their value of Wm under stress condition (D; see text).

Fig. 6 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 6. Mean parasite counts of Neobenedenia sp. infecting the head (A), body (B) and fins (C) of Lates calcarifer over time. 'a', 'b' and 'c' = differences between pairs of means determined using Tukey's HSD test.

Fig. 4 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 4. Neobenedenia sp. mean infection success on Lates calcarifer over time. 'a', 'b' and 'c' = differences between pairs of means determined using Tukey's HSD test, p <0.05.

Fig. 5 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 5. Neobenedenia sp. distribution on the body surface of Lates calcarifer over time. A kernel spatial point analysis was used to estimate the number of parasites/unit of measure2. Dhat values show the rank of the data within 99 simulations of randomly distributed points. Complete spatial randomness is rejected with values between 90 and 100.

Fig. 3 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 3. Live fluorescent Neobenedenia sp. attached to Lates calcarifer over time. Parasites observed attached to fish following 15 min (A), 30 min (B), 2 h (C), 48 h (D), 96 h (E) and 16 d (F) post-infection. Arrow shows the haptor of Neobenedenia sp. A slightly higher exposure was used when photographing parasites at 16 days post-infection to account for faded fluorescence. Scale bar = 100 Mm.

Fig. 1 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 1. Lates calcarifer microhabitat terminology (A) and body surface regions (B) used for statistical analysis. af = anal fin; cf = caudal fin; cp = caudal peduncle; dhf = dorsal hard fin; dsf = dorsal soft fin; e = eye; h = head; m = mandible; mb = middle body; op = operculum; plf = pelvic fin; ptf = pectoral fin; ub = upper body; vb = ventral body. B = body; F = fins; H = head. Terminology is based on Helfman et al. (2009) and Roberts and Ellis (2012).

Fig. 2 in Tracking transparent monogenean parasites on fish from infection to maturity

Fig. 2. Live fluorescent Neobenedenia sp. juveniles attached beneath the scales of Lates calcarifer (A, B) and attached to the surface of the fish scales (C). Parasites are 1 h old (A, B) and 2 h old (C). Scale bar = 100 Mm.

opencc-by-4.0Dec 2016View details →

FIGURE 30. Rhadinacanthus longispinus median fin spines from mature fish, transverse section drawings. 1, 2, posterior dorsal spine NMS G.2014.4.33 in The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland

FIGURE 30. Rhadinacanthus longispinus median fin spines from mature fish, transverse section drawings. 1, 2, posterior dorsal spine NMS G.2014.4.33 from the slates west of East Murkle Bay, Caithness: 1, spine showing position of sections; 2, sections 1–8. 3, section of posterior dorsal spine NMS G.2014.33.2 from North Ronaldsay. 4, section of anterior dorsal spine NMS G.2014.11.1 from Broad Taing, Orkney. Scale bars equal 1 cm in 1; 5 mm in 2; 1 mm in 3, 4.

dryad36/100

Data from: Minimum size limits and the reproductive value of numerous, young, mature female fish

Fisheries management relies on various catch and effort controls to preserve spawning stock biomass and maximise sustainable yields while limiting fishery impacts on marine ecosystems. These include species-specific minimum or maximum size limits to protect either small non-reproductive sub-adults, a portion of reproductively mature adults, or large highly fecund individuals. Protecting size classes of mature fish is expected to yield a viable source of larvae for replenishing populations and reduce the risk of recruitment overfishing, yet size-specific recruitment contributions have rarely been assessed empirically. Here we apply genetic parentage analysis to measure the reproductive success of a size-structured population of a commercially important species of coral grouper (Plectropomus maculatus - Serranidae) in no-take marine reserves in the Great Barrier Reef Marine Park, Australia. Although the per-capita reproductive success of individual fish increases rapidly with body-length, the numerous young mature female fish (NYMFFs), below the minimum size limit (38 cm total length), were responsible for generating disproportionately large contributions (36%) towards larval replenishment of both fished and reserve reefs. Our findings indicate that minimum size limits are an effective harvest control measure to safeguard a portion of the spawning stock biomass for coral grouper and supplement recruitment subsidies assured from no-take marine reserves.

opencc-zeroNov 2020View details →

dryad36/100

Heterogeneous genetic basis of age at maturity in salmonid fishes

Understanding the genetic basis of repeated evolution of the same phenotype across taxa is a fundamental aim in evolutionary biology and has applications to conservation and management. However, the extent to which interspecific life-history trait polymorphisms share evolutionary pathways remains under-explored. We address this gap by studying the genetic basis of a key life-history trait, age at maturity, in four species of Pacific salmon (genus Oncorhynchus) that exhibit intra- and interspecific variation in this trait – Chinook Salmon, Coho Salmon, Sockeye Salmon, and Steelhead Trout. We tested for associations in all four species between age at maturity and two genome regions, six6 and vgll3, that are strongly associated with the same trait in Atlantic Salmon (Salmo salar). We also conducted a genome-wide association analysis in Steelhead to assess whether additional regions were associated with this trait. We found the genetic basis of age at maturity to be heterogeneous across salmonid species. Significant associations between six6 and age at maturity were observed in two of the four species, Sockeye and Steelhead, with the association in Steelhead being particularly strong in both sexes (p = 4.46x10-9 after adjusting for genomic inflation). However, no significant associations were detected between age at maturity and the vgll3 genome region in any of the species, despite its strong association with the same trait in Atlantic Salmon. We discuss possible explanations for the heterogeneous nature of the genetic architecture of this key life-history trait, as well as the implications of our findings for conservation and management.

opencc-zeroJan 2021View details →

Figure 8 in The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

Figure 8. Relationships of the body size groups with the different sagitta constituents: (A) width between ventral margin to crista inferior (CriV); (B) width of the groove of mid dorsal margin (MdGW); (C) depth of the groove of mid dorsal margin (MdGD).

Figure 3 in The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

Figure 3. Comparative relationships between sagitta length, width and weight and fork length in the four groups of Eleutheronema tetradactylum. Here and in Fig. 4: group I (Gr-I) – 11-12 cm FL, group II (Gr-II) – 15-16 cm FL, group III (Gr-III) – 19-20 cm FL, group IV (Gr-IV) – 23-24 cm FL.

Figure 2 in The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

Figure 2. Scanning electron micrographs (SEM) of the medial surface of right sagittae of Eleutheronema tetradactylum: (A) Gr-I, smooth outer margin; (B) Gr-II, pointed antirostrum, deep dorsal depression and bent caudal end with growth stripes, the caudal colliculum includes numerous buttons like concretions, mid-dorsal groove (white arrow); (C) Gr-III, developed rostrum & blunt antirostrum, growth stripes on the ventral wall of sulcus, shallow dorsal depression; (C) Gr-IV, blunt antirostrum, bent caudal end, reduced dorsal depression, granular caudal colliculum.

Figure 6 in The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

Figure 6. Relationships of the body size groups with different sagitta constituents: (A) rostrum length (RL); (B) antirostrum length (ArL); (C) width of excisura major (ExW); (D) ostium length (OL); (E) ostium width (OW); (F) cauda length (Cl).

Figure 5 in The developmental variations of the sagitta otolith in the young and mature male of a hermaphrodite polynemidae fish, Eleutheronema tetradactylum (Shaw, 1804)

Figure 5. Relationships of the body size groups with different sagitta features: (A) sagitta length (OL); (B) sagitta width (OW); (C) sagitta weight (Owt); (D) sulcus length (SL); (E) sulcus width (SW); (F) sulcus depth (SD).