Irregular S-cone mosaics in felid retinas: spatial interaction with axonless horizontal revealed by cross-correlation

In most mammals short-wavelength-sensitive (S) cones are arranged in irregular patterns with widely variable intercell distances. Consequently, mosaics of connected interneurons either may show some type of correlation to photoreceptor placement or may establish an independent lattice with compensatory dendritic organization. Since axonless horizontal cells (A-HC’s) are supposed to direct all dendrites to overlying cones, we studied their spatial interaction with chromatic cone subclasses. In the cheetah, the bobcat, and the leopard, anti-S-opsin antibodies have consistently colabeled the A-HC’s in addition to the S cones. We investigated the interaction between the two cell mosaics, using autocorrelation and cross-correlation procedures, including a Voronoi-based density probe. Comparisons with simulations of random mosaics show significantly lower densities of S cones above the cell bodies and primary dendrites of A-HC’s. The pattern results in different long-wavelength-sensitive-L- and S-cone ratios in the central versus the peripheral zones of A-HC dendritic fields. The existence of a related pattern at the synaptic level and its potential significance for color processing may be investigated in further studies

V-Proportion: a method based on the Voronoi diagram to study spatial relations in neuronal mosaics of the retina

The visual system plays a predominant role in the human perception. Although all components of the eye are important to perceive visual information, the retina is a fundamental part of the visual system. In this work we study the spatial relations between neuronal mosaics in the retina. These relations have shown its importance to investigate possible constraints or connectivities between different spatially colocalized populations of neurons, and to explain how visual information spreads along the layers before being sent to the brain. We introduce the V-Proportion, a method based on the Voronoi diagram to study possible spatial interactions between two neuronal mosaics. Results in simulations as well as in real data demonstrate the effectiveness of this method to detect spatial relations between neurons in different layers

Određivanje lektotipa Canestrinijevog glavoča, Gobius canestrinii Ninni, 1883 (Teleostei, Gobiiformes, Gobiidae, Gobionellinae)

A recent study based on molecular biological data revealed that Gobius canestrinii (Ninni, 1883), a gobioid fish endemic to the Adriatic basin, has to be split in three lineages. The original description was based on populations from two distant localities in Italy and in Croatia respectively, the first representing one of these lineages, the second most likely belonging to another lineage. To fix the name of the species, we hereby designated a lectotype for Canestrini’s Goby.Nedavna istraživanja, zasnovana na molekularno biološkim metodama, otkrila su da se Gobius canestrinii (Ninni, 1883), endemski glavoč jadranskog bazena, dijeli u tri filogenetske grane. Izvorni opis vrste zasnivao se na populacijama dva udaljena lokaliteta u Italiji i Hrvatskoj. Populacija u Italiji predstavlja jednu od tri filogenetske grane, dok druga najvjerojatnije predstavlja jednu od preostale dvije grane. Da bi se fiksiralo ime vrste, u ovom radu određujemo lektotip Canestrinijevog glavoča

Koliko je jedinki britke jedroglavke, Lophotus lacepede Giorna, 1809 (Pisces: Lophotidae), ulovljeno u Jadranu?

In this paper the status of crested oarfish Lophotus lacepede Giorna, 1809 (Pisces: Lophotidae) is checked with precise information from records of this species in the Adriatic Sea. According to presented data it was concluded that just five confirmed records were noted in the Adriatic Sea. Finally, it should be noted that the crested oarfish is very rare species in the Adriatic Sea.U ovom radu je obavljena analiza broja ulovljenih jedinki britke jedroglavke Lophotus lacepede Giorna, 1809 (Pisces: Lophotidae) uz pregled točnih i potvrdnih nalaza ove vrste u Jadranu. Suglasno dobivenim rezultatima može se zaključiti da je do sada potvrđeno samo pet nalaza ove vrste u Jadranu. Na kraju, može se na osnovi broja potvrdnih nalaza utvrditi da je ova vrsta vrlo rijetka za Jadran

Das Coelom der Chaetognathen

Die vorliegende Arbeit hatte die Klärung verschiedener phylogenetisch relevanter Fragen der Chaetognathen-Anatomie auf ultrastruktureller Ebene zum Thema Die Leibeshöhlen der Chaetognathen bilden ein funktions-adäquat kompartimentiertes hydrostatisches System. Bei meisten untersuchten Gattungen (Ausnahme:Spadella) bildet das Rumpfcölom ein weites flüssigkeitsgefülltes Lumen mit Cilienepithelien als Zirkulationseinrichtung. Die longitudinale Hauptmuskulatur ist als mehrreihiges Epithel ausgebildet, dessen Zellen bei den kleinen Arten zwei terminale Ansatzstellen aufweisen, bei den großen Sagitten jedoch kontinuierlich an der Basallamelle ansetzen. Auf Grund der Organisation der kollagenen Fibrillen fungiert die ekto-mesodermale Basallamelle als Muskelantagonist und setzt einwirkenden Zug- und Druckkräften gleichermaßen elastischen Widerstand entgegen (in Verbindung mit einem ausgedehnten Tonofibrillen-Mantels in den Epidermiszellen und mit dem cölomatischen Turgor). Bei den Großformen innerhalb der Gattung Sagitta wird durch überproportionale Ausweitung und entsprechende Formgebung des Rumpf- und Schwanzcöloms ein Strömungsprofil mit geringem Widerstandsbeiwert erreicht. Im basiepithelialen Plexus ist als Folge seiner teilweisen Korrelation mit der Hauptmuskulatur eine Pseudo-Neuromerie ausgebildet. er Verlauf der Basallamellen bestätigt trotz des Fehlens eines zusätzlichen Cölothels den cölomaten Status der Leibeshöhle der Chaetognathen. Die Struktur der Septen stellt die Hypothese einer primär trimeren Organisation des Antedeszendenten der rezenten Chaetognathen in Frage. Die Ergebnisse haben für die meisten Strukturen Merkmale erbracht, die in hohem Grad als mit Funktionen korreliert erscheinen und somit einen Status als Analogien bzw. Homoiologien wahrscheinlich machen. Erst auf der Basis der Untersuchung weiterer seltenerer Gattungen wird es zu rechtfertigen sein, morphologische Reihen zu erstellen die Beziehungen der Arten innerhalb des Phylums und des Phylums zu den übrigen Metazoen klären können.This work on chaetognath (ultra-) structure was undertaken to clarify questions with relevance for the classification of the group in the system of metazoan systematics and phylogeny. Main results – besides a number of novel observations on other body systems: The body cavity is an adequately compartmented hydrostatic system. The head coelom allows for the positional changes of the gripping apparatus during capture of prey. In most genera studied the trunk coelom is a lumen filled with fluid circulating by cilia arising from a lateral mesodermal epithelial streak. Due to the organization of its collagen fibrils, the basal lamina - in synergy with the coelomic turgor - acts as an antagonist to the trunk musculature. Its course confirms the coelomate status of the body cavity despite the absence of an additional coelothelium. The main longitudinal musculature is designed as a multi-row epithelium. Each cell has two points of attachment to the basal lamina in smaller species, while in Sagitta they are attached continuously. In the basi-epithelial plexus a pseudo-neuromeria results from its correlation with the main muscles. The septal structure puts the hypothesis of a primarily trimeric organization of the Chaetognaths ancestors into question. The studies have revealed a close correlation of most structures with their function, thus impeding clear differentiation of analogies or homoiologies from homologies. Thus it seems necessary to extend future ultrastructural studies to the less common Chaetognath genera to further elucidate the relationship of species within the phylum and of the phylum to the remaining metazoans

Temperature-Dependent Reproductive Success of Stickleback Lateral Plate Morphs: Implications for Population Polymorphism and Range Shifts Under Ocean Warming

Changing environments associated with rapid climate change can shape direct measures of fitness such as reproductive success by altering mating behavior, fecundity and offspring development. Using a polymorphic oceanic population of threespine stickleback (Gasterosteus aculeatus), we investigated whether a 4�°C increase in sea surface temperature influenced clutch siring success, reproductive output, and offspring growth among lateral plate morphs. Since low plated morphs are thought to have a selective advantage in warmer environments, we predicted that low plated males should have higher clutch siring success in +4�°C environments, and that thermal plasticity of traits (e.g., egg size, offspring growth) should reflect different trait optima in different environments among plate morphs. Parentage analysis of egg clutches revealed temperature-specific clutch siring success, in that low plated males sired more clutches in +4�°C environments and completely plated males sired more clutches at ambient (seasonal) temperature. Both completely and low plated females laid larger eggs when acclimated to +4�°C, but only completely plated females had smaller clutches at +4�°C. Offspring of low and partially plated females grew much less at +4�°C compared to those of completely plated females. Taken together, our results demonstrate that ocean warming could impact reproductive success at various levels, with differential effects depending on phenotype, in this case, lateral plate morph. Some traits (clutch siring success, egg size) showed better performance for low plated fish at +4�°C, whereas others (e.g., growth) did not. Higher clutch siring success of low plated males at elevated temperature might indicate a future shift in plate morph composition for polymorphic stickleback populations, with potential implications for colonization ability during range shifts under climate change

Temperature-Dependent Reproductive Success of Stickleback Lateral Plate Morphs: Implications for Population Polymorphism and Range Shifts Under Ocean Warming

Changing environments associated with rapid climate change can shape direct measures of fitness such as reproductive success by altering mating behavior, fecundity and offspring development. Using a polymorphic oceanic population of threespine stickleback (Gasterosteus aculeatus), we investigated whether a 4°C increase in sea surface temperature influenced clutch siring success, reproductive output, and offspring growth among lateral plate morphs. Since low plated morphs are thought to have a selective advantage in warmer environments, we predicted that low plated males should have higher clutch siring success in +4°C environments, and that thermal plasticity of traits (e.g., egg size, offspring growth) should reflect different trait optima in different environments among plate morphs. Parentage analysis of egg clutches revealed temperature-specific clutch siring success, in that low plated males sired more clutches in +4°C environments and completely plated males sired more clutches at ambient (seasonal) temperature. Both completely and low plated females laid larger eggs when acclimated to +4°C, but only completely plated females had smaller clutches at +4°C. Offspring of low and partially plated females grew much less at +4°C compared to those of completely plated females. Taken together, our results demonstrate that ocean warming could impact reproductive success at various levels, with differential effects depending on phenotype, in this case, lateral plate morph. Some traits (clutch siring success, egg size) showed better performance for low plated fish at +4°C, whereas others (e.g., growth) did not. Higher clutch siring success of low plated males at elevated temperature might indicate a future shift in plate morph composition for polymorphic stickleback populations, with potential implications for colonization ability during range shifts under climate change