From Microscale Interactions to Macroscale Patterns in Copepod-Crinoid Symbiosis.

Crinoids (Echinodermata) exhibit unique morphological and behavioral characteristics that facilitate a wide range of symbiotic relationships with diverse organisms. Our comprehension of their interactions with microscopic copepod crustaceans is, however, still in a nascent and fragmented state. Here, we review and discuss the 166 literature records to date in which a total of 39 copepod species in 6 families have been reported in association with 33 species of the crinoid order Comatulida. Many of these associations have been reported just once. The respective localities cover 5 of the World Ocean's 12 ecoregions, with a notable concentration of both host and symbiont diversity in the Central and Western Indo-Pacific. In contrast, the documentation of copepod-crinoid associations in the Atlantic appears markedly limited. Copepods have been found predominantly in ectosymbiotic relationships with crinoids, with a lower incidence of endosymbiosis. Copepods of the genera Collocheres Canu, 1893 and Pseudanthessius Claus, 1889 are particularly prominent in the list, and the comatulid family Comatulidae displays the most diverse assortment of copepod associations. The current scope of knowledge encompasses a mere 5% of the potential crinoid host diversity, underscoring the need for more extensive research in this area.

Crinoidea y Asteroidea (Echinodermata) del talud de la península de Yucatán, de la Colección Nacional de Equinodermos de México / Crinoidea and Asteroidea (Echinodermata) from the slope of the Yucatan Peninsula, Colección Nacional de Equinodermos, Mexico

Resumen Introducción: Las especies de las clases Crinoidea y Asteroidea se distribuyen en gran variedad de hábitats en todos los océanos desde la zona intermareal hasta grandes profundidades, existen pocos registros en aguas mexicanas, a profundidades superiores a los 200 m, los escasos registros existentes datan de documentos históricos de la literatura especializada y los ejemplares se resguardan en colecciones científicas extranjeras. Objetivo: Contribuir a la recopilación de información de los ejemplares resguardados en la Colección Nacional de Equinodermos (CNE) del Instituto de Ciencias del Mar y Limnología (ICML), UNAM y proveer un inventario de las especies de crinoideos y asteroideos que habitan en zonas profundas del talud de la Península de Yucatán, México. Métodos: Del año 2005 al 2014 se recolectaron ejemplares de crinoideos y asteriodeos en cuatro cruceros en el B/O "Justo Sierra" BIOREPES 1 y 2 y COBERPES 2 y 6. Se realizaron arrastres con red camaronera en 80 estaciones de muestreo. Resultados: El listado taxonómico comprende 1146 ejemplares, de los cuales 204 son crinoideos del orden Comatulida, distribuidos en tres familias tres géneros y tres especies y 942 asteroideos distribuidos en seis órdenes, 11 familias, 21 géneros y 28 especies. Se obtuvieron los registros nuevos para la CNE: Democrinus rawsonii y Atelecrinus balanoides en crinoideos. Astropecten alligator, Hymenaster modestus, Calyptraster personatus, Pteraster militarioides militarioides, Sclerasterias contorta en asteroideos. Con esta información se incrementan los registros de crinoideos y asteroideos (de profundidad mayor a 200 m) para los estados de Yucatán (16) y Quintana Roo (16).

Abstract Introduction: The species of the Crinoidea and Asteroidea classes are distributed in a wide variety of habitats in all oceans from the intertidal zone to great depths, there are few Mexican records in depths greater than 200 m, the few existing records date from historical documents in the specialized literature and the specimens are kept in foreign scientific collections. Objective: Contribute to the collection of information on the specimens kept in the Colección Nacional de Equinodermos (CNE) of Instituto de Ciencias del Mar y Limnología (ICML), UNAM and provide an inventory of the species of crinoids and asteroids that inhabit deep areas of the slope of the Yucatan Peninsula, Mexico. Methods: From 2005 to 2014, specimens of crinoids and asterioids were collected through four cruises in the B/O "Justo Sierra" BIOREPES 1 and 2 and COBERPES 2 and 6, shrimp net trawls were carried out at 80 sampling stations. Results: The taxonomic list includes 1146 specimens, of which 204 crinoids are of the order Comatulida, distributed in three families, three genera and three species and 942 asteroids distributed in six orders, 11 families, 21 genera and 28 species. New records were obtained for CNE: Democrinus rawsonii and Atelecrinus balanoides in crinoids. Astropecten alligator, Hymenaster modestus, Calyptraster personatus, Pteraster militarioides militarioides, Sclerasterias contorta in asteroids. With this information, the records of crinoids and asteroids (deeper than 200 m) increase for the states of Yucatan (16) and Quintana Roo (16).

Phanogracilins A-C, New Bibenzochromenones of Crinoid Phanogenia gracilis (Hartlaub, 1890).

Three new bibenzochromenones named phanogracilins A-C (1-3) were isolated from the crinoid Phanogenia gracilis. The structure of 1 was established using X-ray crystallography as 5,5',6,6',8,8'-hexahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4'-dione. This allowed us to assign reliably 2D NMR signals for compound 1 and subsequently for its isomer 2 that differed in the connecting position of two benzochromenone moieties (7,10' instead of 7,9'), and compound for 3 that differed in the length of the aliphatic chain of one of the fragments. Compound 4 was derived from 1 in alkaline conditions, and its structure was elucidated as 5,5',6',8,8'-pentahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4',6,9-tetraone. Even though compounds 1-4 did not contain stereo centers, they possessed notable optical activity due to sterical hindrances, which limited the internal rotation of two benzochromenone fragments around C(7)-C(9'/10') bonds. Isolated bibenzochromenones 1-4 were tested for their antiradical, neuroprotective and antimicrobial activities. Compounds 1, 3 and 4 demonstrated significant antiradical properties towards ABTS radicals higher than the positive control trolox. Compounds 1 and 4 exhibited moderate neuroprotective activity, increasing the viability of rotenone-treated Neuro-2a cells at a concentration of 1 µM by 9.8% and 11.8%, respectively. Compounds 1 and 3 at concentrations from 25 to 100 µM dose-dependently inhibited the growth of Gram-positive bacteria S. aureus and yeast-like fungi C. albicans, and they also prevented the formation of their biofilms. Compounds 2 and 4 exhibited low antimicrobial activity.

Regeneration of the digestive system in the crinoid Lamprometra palmata (Mariametridae, Comatulida).

The morphology and regeneration of the digestive system and tegmen after autotomy of the visceral mass in the crinoid Lamprometra palmata (Clark 1921) was studied. The gut has a five-lobed shape and is covered by a tegmen. The tegmen consists of epidermis and underlying connective tissue. The digestive tube can be divided into three parts: esophagus, intestine, and rectum. At 6 h post-autotomy, the calyx surface is covered by a layer of amoebocytes and juxtaligamental cells (JLCs). At 14-18 h, post-autotomy transdifferentiation of JLCs begins and give rise to the epidermis and cells of digestive system. On days 1-2 post-autotomy, JLCs undergo the mesenchymal-epithelial transition. Some JLCs turn into typical epidermal cells, while other JLCs form small closed epithelial structures that represent the gut anlage. On day 4 post-autotomy, the animals have a mouth opening and a small anal cone. On day 7 post-autotomy, the visceral mass and the digestive system become fully formed but are smaller than normal. A 24-h exposure of L. palmata individuals to a 10-7 M colchicine solution did not slow down regeneration, and the timing of gut formation was similar to that in the control animals. We conclude that JLCs are the major cell source for gut and epidermis regeneration in L. palmata. The main mechanisms of morphogenesis are cell migration, mesenchymal-epithelial transition, and transdifferentiation.

Ausichicrinites zelenskyyi gen. et sp. nov., a first nearly complete feather star (Crinoidea) from the Upper Jurassic of Africa.

Fossil comatulids, referred to as feather stars, are mostly known from highly disarticulated specimens. A single isolated element (centrodorsal) has been the basis for taxonomic description of a vast majority of fossil comatulids. Here, we report a nearly complete, and thus extremely rare, comatulid from the Upper Jurassic (Tithonian) of the Blue Nile Basin in central western Ethiopia that provides a unique insight into the morphology of comatulid arms and cirri. It is assigned to Ausichicrinites zelenskyyi gen. et sp. nov. and is the first Jurassic comatulid from the African continent. The new taxon shows some similarities with representatives of the Mesozoic Solanocrinitidae but also has close resemblance with the modern family Zygometridae, exclusively known from the Holocene of western Pacific and eastern Indian Oceans. This morphologic similarity is considered to be due to convergence. The first example of pinnule regeneration in a fossil feather star is reported, which reinforces the hypothesis about the importance of predation in the evolution of these crinoids.

Complete mitochondrial genome of the feather star Cenometra bella (Hartlaub, 1890) (Crinoidea: Colobometridae).

The complete mitochondrial genome of the feather star Cenometra bella was sequenced in this study. The mitogenome is 15,872 bp in length, with 13 PCGs, 22 tRNA, and two rRNA, and nucleotide composition was as follows: 24.38% A, 47.79% T, 11.16% C, and 16.68% G. Phylogenetic analyses place C. bella as closely related to Stephanometra indica, consistent with previous inferences.

Unraveling the hidden paleobiodiversity of the Middle Devonian (Emsian) crinoids (Crinoidea, Echinodermata) from Poland.

Most previous publications on Devonian crinoids from the Holy Cross Mountains in Poland have concentrated on crinoid columns, and until now, little has been published about crinoid cups and calyxes. Herein, five crinoid taxa are described from an abundant occurrence of aboral cups and partial crowns from the Bukowa Góra Member (Emsian) in the Holy Cross Mountains of southern Poland. The following taxa are described: Bactrocrinites sp., Codiacrinus sevastopuloi sp. nov., Halocrinites geminatus (Bohatý, 2005), Halocrinites schlotheimii Steininger, 1831, and a single brachial plate from a flexible crinoid placed in Flexibilia incertae sedis. Simple discoid holdfasts are also present encrusted to cylindrical stromatoporoids. These taxa are the first crinoids described from the remains of partial crowns from Emsian strata of Poland.

Substrate type and palaeodepth do not affect the Middle Jurassic taxonomic diversity of crinoids.

Crinoids are largely considered as good indicators for determining environmental conditions. They are robust proxies for inferring changes in salinity and sedimentation rate and for inferring substrate type. Some crinoid groups (e.g., certain comatulids, cyrtocrinids, millericrinids) have a depth preference, thus, making them useful for palaeodepth estimation. The hypotheses that crinoid distribution is substrate-dependent (rock type) or palaeodepth-dependent is tested here based on (a) archival Bathonian-Callovian (Middle Jurassic) crinoid occurrences from Poland and (b) newer finds from five boreholes from eastern Poland. Qualitative data suggests that isocrinids and cyclocrinids occur in both carbonate and siliciclastic rocks. The cyrtocrinids and roveacrinids occur within carbonate rocks, whereas the comatulids are exclusive to siliciclastics. In terms of palaeodepth, most crinoid groups dominate in shallow environments with the sole exception of cyrtocrinids, that are ubiquitous and occur in both shallow (near shore and shallow marine) and slightly deeper (deeper sublittoral to open shelf) settings. The occurrences of the cosmopolitan taxa, Chariocrinus andreae and Balanocrinus subteres (isocrinids), is independent of both substrate type and palaeodepth. Quantitative analyses (Analysis Of Variance; ANOVA) based on substrate type, i.e., substrate-dependency (claystones, sandstones and limestones), and palaeodepth i.e., palaeodepth-dependency (near shore, shallow-marine, mid-ramp and offshore), corroborate qualitative results. Statistical analysis suggest that the distribution of crinoids shows a strong substrate-dependency but not for palaeodepth, although very weak significance (low p value) is noted for near shore and shallow marine settings and crinoid distribution.

Notes on some crinoid associated decapod crustaceans (Crustacea: Decapoda) of Lakshadweep Archipelago, Central Indian Ocean.

Decapod crustaceans symbiotic with echinoderms (sea stars, brittle stars, feather stars, basket stars, sea cucumbers, and sea urchins) possess remarkable diversification in the Indo-Pacific. In the present study, seven species of decapod crustaceans symbiotic with crinoids are recorded based on collections from selected Islands (Agatti, Amini, Bangaram, Kavaratti, Kalpeni, and Minicoy) of Lakshadweep Archipelago. Of these decapods, five caridean shrimps (Alpheidae: Synalpheus carinatus (de Man, 1888), S. comatularum (Haswell, 1882), S. stimpsonii (de Man, 1888); Palaemonidae: Palaemonella pottsi (Borradaile, 1915), Pontoniopsis comanthi (Borradaile, 1915), one brachyuran crab [Pilumnidae: Permanotus purpureus (Gordon, 1934)] and one squat lobster [Galatheidae: Allogalathea elegans (Adams White, 1848)] were identified. The caridean shrimps have associated with the crinoids Comaster multifidus (Müller, 1841), Phanogenia gracilis (Hartlaub, 1893), P. distincta (Carpenter, 1888), P. multibrachiata (Carpenter, 1888) and Stephanometra indica (Smith, 1876). The brachyuran crab was observed in association with the crinoid Phanogenia gracilis whereas the squat lobsters were associated with Stephanometra tenuipinna (Hartlaub, 1890) and S. indica. Except S. stimpsonii and P. purpureus, all other species were recorded for the first time from India. Here, we provide details on morphology, distribution, habitat, and hosts for all species. We recommend further exploration of the sub-shallow coral reef areas of Lakshadweep as there will be many species that certainly remain to be discovered.

Minor and trace elements in skeletons of Arctic echinoderms.

We report the ratios of minor (K/Ca, Na/Ca, P/Ca, S/Ca) and trace elements (Al/Ca, Ba/Ca, Fe/Ca, Mn/Ca and Zn/Ca) in skeletons of five Arctic echinoderm species representing three classes: Asteroidea, Ophiuroidea, Crinoidea. We found that skeletons of Arctic echinoderms show a unique, species-specific trace element composition that may suggest that incorporation of elements into the skeleton is biologically controlled by the organism. On the other hand, the concentration of some minor elements in skeletal parts exhibit patterns that are consistent with elemental concentrations in seawater, indicating that formation of echinoderm skeletons is environmentally controlled. Seawater is the main source of ions and compounds needed for skeletal formation and maintaining similar concentrations most likely reduces the biological cost related to selective uptake of ions. Additionally, Al, Ba, Fe, Mg and Mn showed station specific variation in elemental concentration which again suggests that accumulation of metals can be shaped by environmental concentrations.

Significance of crinoid preservation: Clare Shale Formation (Upper Carboniferous), Fisherstreet Bay, Doolin, County Clare, Ireland.

Some fossils, such as crinoid stems, are not widely appreciated by collectors and researchers, yet can provide unique data regarding taphonomy and palaeoecology. A long crinoid pluricolumnal showing a distinctive pattern of preservation was collected from the Clare Shale Formation (Upper Carboniferous) at Fisherstreet Bay, Doolin, County Clare, western Ireland. The specimen is partly disarticulated and represents the mesistele to mesistele/dististele transition; attachment was by unbranched long, slender radices; pluricolumnal heteromorphic; fragments of pluricolumnal are of multiples of a unit length. This specimen, cladid? sp. indet., slumped to the seafloor after death and started to disarticulate as ligaments rotted. By reference to the broken stick model, the pattern of disarticulation suggests that the noditaxis of the heteromorphic stem was N212.

Nervous system characterization during the development of a basal echinoderm, the feather star Antedon mediterranea.

Neural development of echinoderms has always been difficult to interpret, as larval neurons degenerate at metamorphosis and a tripartite nervous system differentiates in the adult. Despite their key phylogenetic position as basal echinoderms, crinoids have been scarcely studied in developmental research. However, since they are the only extant echinoderms retaining the ancestral body plan of the group, crinoids are extremely valuable models to clarify neural evolution in deuterostomes. Antedon mediterranea is a feather star, endemic to the Mediterranean Sea. Its development includes a swimming lecithotrophic larva, the doliolaria, with basiepithelial nerve plexus, and a sessile filter-feeding juvenile, the pentacrinoid, whose nervous system has never been described in detail. Thus, we characterized the nervous system of both these developmental stages by means of immunohistochemistry and, for the first time, in situ hybridization techniques. The results confirmed previous descriptions of doliolaria morphology and revealed that the larval apical organ contains two bilateral clusters of serotonergic cells while GABAergic neurons are localized under the adhesive pit. This suggested that different larval activities (e.g., attachment and metamorphosis) are under the control of different neural populations. In pentacrinoids, the analysis showed the presence of a cholinergic entoneural system while the ectoneural plexus appeared more composite, displaying different neural populations. The expression of three neural-related microRNAs was described for the first time, suggesting that these are evolutionarily conserved also in basal echinoderms. Overall, our results set the stage for future investigations that will reveal new information on echinoderm evo-devo neurobiology.

A Prejudiced Review of Ancient Parasites and Their Host Echinoderms: CSI Fossil Record or Just an Excuse for Speculation?

Recognizing the presence of a parasite and identifying it is a relatively straightforward task for the twenty-first century parasitologist. Not so the pursuit of ancient parasites in fossil organisms, a much more difficult proposition. Herein, Boucot's seven-tiered scheme of reliability classes is applied as a measure of confidence of the recognition of putative parasitism in two echinoderm classes, Upper Palaeozoic crinoids and a Cretaceous echinoid (high confidence is 1, low confidence 7). Of the five examples, the parasitic(?) organism is preserved in only two of them. A zaphrentoid coral on the camerate crinoid Amphoracrinus may have robbed food from the arms (Category 1 or 2B). A pit in what appears to be a carefully selected site on the disparid crinoid Synbathocrinus is associated with a growth deformity of the cup (Category 4). Multiple pits in an Amphoracrinus theca are also associated with a deformed cup, but it is more difficult to interpret (Category 4 or 7). Some specimens of the camerate crinoid Neoplatycrinites have circular grooves or depressions posteriorly, presumably produced by coprophagic/parasitic platyceratid gastropods (Category 1). Site selectivity of pits in the echinoid Hemipneustes places them preferentially adjacent to respiratory tube feet (Category 4). From these examples it is deduced that sparse infestations of borings or epizoozoic organisms permit a more confident interpretation of organism/organism interactions; dense accumulations, possibly following multiple spatfalls, mask such patterns.

Troglomorphism in the middle Triassic crinoids from Poland.

In this paper, we document the Middle Triassic marine fauna recovered from the fissure/cave system of Stare Gliny (southern Poland) developed in the Devonian host dolomite. The fossils are mostly represented by in situ preserved and small-sized holdfasts of crinoids (Crinoidea) that are attached to the cave walls. Other fossils found in the cave infills include articulated brittle stars and brachiopods. Our findings constitute the oldest Mesozoic evidence for troglophile crinoids. We suggest that troglomorphism in these echinoderms was likely related to protection against predation, which underscores the magnitude of anti-predatory adaptations to increased predation pressure that occurred during the Early Mesozoic Marine Revolution.

Roveacrínidos (Crinoidea: Roveacrinida) del Cenomaniano tardío al Turoniano temprano de Cerritos, oeste de la Plataforma Valles-San Luis Potosí, México / Roveacrinids (Crinoidea: Roveacrinida) from the late Cenomanian to early Turonian from Cerritos, western Valles-San Luis Potosí Platform, Mexico

Resumen Se estudiaron crinoideos roveacrínidos procedentes de afloramientos de la Formación Soyatal (Cenomaniano superior-Turoniano inferior) ubicados en la localidad de Cerritos (22º01'00" N -100º 57' 00" W) que se ubica en la parte occidental de la Plataforma valles-San Luis Potosí, México. Los roveacrínidos fueron identificados con las especies Roveacrinus geinitzi Schneider, 1989, Poecilocrinus dispandus elongatus Peck, 1943 y Roveacrinus sp. Estos microcrinoideos se estudiaron en secciones delgadas y están representados únicamente por fragmentos de las placas de la teca y de las braquiolas. Los roveacrínidos son organismos de formas oportunistas que se desarrollaron durante cambios del nivel del mar. Los roveacrínidos se encuentran asociados a un auge de calcispheras y a foraminíferos planctónicos de estrategia r y r-k como Muricohedbergella delrioensis (Carsey), M. planispira (Tappan), Heterohelix moremani (Cushman), Heterohelix reussi (Cushman), Whiteinella archaeocretacea Pessagno, W. aprica (Loeblich &Tappan), W. brittonensis (Loeblich & Tappan), W. baltica Douglas and Rankin, y W. paradubia (Sigal), lo cuales se consideran como indicadores de alta productividad primaria en un ambiente inestable que tuvo lugar durante la inundación de la Plataforma valles-San Luis Potosí en el límite Cenomaniano/Turoniano.

Abstract Fragments of roveacrinid crinoids of the upper Cenomanian-lower Turonian from Soyatal Formation located in the western part of the valles-San Luis Potosí Platform, Mexico, were studied. Roveacrinid fossils consist of small pieces of cup and brachials observed in thin sections that were identified with the species Roveacrinus geinitzi Schneider 1989, Poecilocrinus dispandus elongatus Peck 1943 and Roveacrinus sp. The Roveacrinids are opportunist organisms that developed during changes of sea level. The roveacrinids are associated with a calcispherids bloom and r and r-k strategy planktonic foraminifers, such as Muricohedbergella delrioensis (Carsey), M. planispira (Tappan), Heterohelix moremani (Cushman), Heterohelix reussi (Cushman), Whiteinella archaeocretacea Pessagno, W. aprica (Loeblich & Tappan), W. brittonensis (Loeblich &Tappan), W. balticaDouglas & Rankin, and W. paradubia (Sigal), which are considered as indicators of high primary productivity in an unstable environment that took place during the flooding of the valles-San Luis Potosí Platform in the Cenomanian/Turonian boundary. Rev. Biol. Trop. 63 (Suppl. 2): 17-25. Epub 2015 June 01.

Persistent and widespread occurrence of bioactive quinone pigments during post-Paleozoic crinoid diversification.

Secondary metabolites often play an important role in the adaptation of organisms to their environment. However, little is known about the secondary metabolites of ancient organisms and their evolutionary history. Chemical analysis of exceptionally well-preserved colored fossil crinoids and modern crinoids from the deep sea suggests that bioactive polycyclic quinones related to hypericin were, and still are, globally widespread in post-Paleozoic crinoids. The discovery of hypericinoid pigments both in fossil and in present-day representatives of the order Isocrinida indicates that the pigments remained almost unchanged since the Mesozoic, also suggesting that the original color of hypericinoid-containing ancient crinoids may have been analogous to that of their modern relatives. The persistent and widespread occurrence, spatially as well as taxonomically, of hypericinoid pigments in various orders during the adaptive radiation of post-Paleozoic crinoids suggests a general functional importance of the pigments, contributing to the evolutionary success of the Crinoidea.