Occurrence of microdebris in commercial cephalopod

Modern Fish Market of Muara Baru is one of the largest fish markets in Jakarta, which sells various seafood, including fish, shellfish, crustaceans, and others. Previous studies have revealed microdebris contamination of mollusks, particularly in filter-feeders. However, it has not been widely studied at the predator level in cephalopods. We aim to investigate contamination of microdebris in two commercial species of cephalopod, i.e. Loliolus sumatrensis and Sepia recurvirostra, from the market. The digestive tract of the cephalopod was taken and dissolved by adding H2O2 50% then filtered under a vacuum system. The particles of microdebris were observed with a stereo microscope then several particles were analyzed using an FTIR microscope. The abundance of microdebris in L. sumatrensis was higher (3.8 particles/individual) than the abundance that of microdebris in S. recurvirostra (2.8 particles/individual). The size of microdebris was dominated by three of five size classes such as 0.1 − 0.5 mm, 0.5 − 1 mm, and 1 − 5 mm. Microdebris in L. sumatrensis was confirmed as polypropylene (PP), a synthetic polymer (microplastic), while in S. recurvirostra was confirmed as rayon (semi-synthetic). This research shows that microdebris contamination has reached the level of a predator in Mollusca.

Intertidal Community Differences Between the Cook Strait and Wellington Harbour

<p>Wellington Harbour which lies near the southern tip of the North Island, New Zealand, exhibits a typical rocky intertidal shoreline with groups of species similar to those found on many temperate rocky coasts around the world. A short distance away, the Cook Strait displays a very different shoreline in community composition compared with Wellington Harbour, most notably a distinct lack of filter feeders. This thesis aims to examine how exactly the community composition is different between the two coasts at a species level and if there are any environmental factors that can explain the differing distributions. Here, a series of field and laboratory experiments aim to examine why certain filter feeders (mussels) are absent from the Cook Strait shore, yet so abundant in Wellington Harbour ... This work indicates that the Cook Strait coastline has lower filter feeder abundances and an overall different community composition than Wellington Harbour. The cause of these differences appears to be bottom up regulation through the lack of food availability (phytoplankton) during winter months in the Cook Strait. The high commercial value of coastal environments in both fisheries and tourism heightens the need to understand these habitats. Unravelling the complex relationships between the seasonal changes in the water column and onshore biota is important for conserving and protecting these essential ecosystems in New Zealand and temperate shores worldwide.</p>

Intertidal Community Differences Between the Cook Strait and Wellington Harbour

<p>Wellington Harbour which lies near the southern tip of the North Island, New Zealand, exhibits a typical rocky intertidal shoreline with groups of species similar to those found on many temperate rocky coasts around the world. A short distance away, the Cook Strait displays a very different shoreline in community composition compared with Wellington Harbour, most notably a distinct lack of filter feeders. This thesis aims to examine how exactly the community composition is different between the two coasts at a species level and if there are any environmental factors that can explain the differing distributions. Here, a series of field and laboratory experiments aim to examine why certain filter feeders (mussels) are absent from the Cook Strait shore, yet so abundant in Wellington Harbour ... This work indicates that the Cook Strait coastline has lower filter feeder abundances and an overall different community composition than Wellington Harbour. The cause of these differences appears to be bottom up regulation through the lack of food availability (phytoplankton) during winter months in the Cook Strait. The high commercial value of coastal environments in both fisheries and tourism heightens the need to understand these habitats. Unravelling the complex relationships between the seasonal changes in the water column and onshore biota is important for conserving and protecting these essential ecosystems in New Zealand and temperate shores worldwide.</p>

Presence of microplastics in jellyfish (Crambionella orsini) along the Kenyan coast

Microplastics are plastic particles less than 5 mm in diameter. These plastics mostly result from degradation of larger plastics. Due to their small size, they are often accidentally ingested by sea faunas, particularly the deposit and filter feeders. However, information on the ingestion of microplastics by sea fauna such as jellyfish is rare. This paper provides evidence of ingestion of microplastics by jelly fishes (Crambionella orsini) along the Kenyan Coast. Samples were taken from three stations (Mikindani and Makupa in Mombasa, and Dabaso in Mida Creek) between 31st January 2018 and 3rd February 2018 using tow nets. Samples were digested using 10 % KOH at 60 °C for 24 hrs and sieved through a 38 µm sieve. Products below 38 µm were filtered using a 0.8 µm Whatman filters, then dried in an oven and viewed under a dissecting microscope for microplastics. Suspected microplastics were confirmed using a hot needle test. Microplastics obtained were mainly fibres of different colours: black, blue, green, colourless, purple, red and yellow. Colourless fibres were the majority accounting for 53 % of the total number of fibres while purple fibres were the least at only 1 %. Mean concentration of microplastics was highest in Dabaso (0.05 mp/g of tissue), whereas in Mikindani and Makupa were almost equal (i.e., 0.03 ± 0.003 mp/g in Mikindani, and 0.03 ± 0.01 mp/g in Makupa). Statistically, the means were not significantly different between the stations (F1, 2 = 1.34; P = 0.43). This study presents evidence of contamination of the Kenyan coastal waters by microplastics and their ingestion by sea fauna such as jellyfish. Results of this study will help reinforce the plastic ban in the country to prevent further accumulation in the environment.

Morphological variation of the relictual alveolar structures in the mandibles of baleen whales

Living baleen whales (mysticetes) are bulk filter feeders that use keratinous baleen plates to filter food from prey laden water. Extant mysticetes are born entirely edentulous, though they possess tooth buds early in ontogeny, a trait inherited from toothed ancestors. The mandibles of extant baleen whales have neither teeth nor baleen; teeth are resorbed in utero and baleen grows only on the palate. The mandibles of extant baleen whales also preserve a series of foramina and associated sulci that collectively form an elongated trough, called the alveolar groove. Despite this name, it remains unclear if the alveolar groove of edentulous mysticetes and the dental structures of toothed mammals are homologous. Here, we describe and quantify the anatomical diversity of these structures across extant mysticetes and compare their variable morphologies across living taxonomic groups (i.e., Balaenidae, Neobalaenidae, Eschrichtiidae, and Balaenopteridae). Although we found broad variability across taxonomic groups for the alveolar groove length, occupying approximately 60–80 percent of the mandible’s total curvilinear length (CLL) across all taxa, the relictual alveolar foramen showed distinct patterns, ranging between 15–25% CLL in balaenids, while ranging between 3–12% CLL in balaenopterids. This variability and the morphological patterning along the body of the mandible is consistent with the hypothesis that the foramina underlying the alveolar groove reflect relictual alveoli. These findings also lay the groundwork for future histological studies to examine the contents of these foramina and clarify their potential role in the feeding process.

Spatial Distribution Patterns of Appendicularians in the Drake Passage: Potential Indicators of Water Masses?

Appendicularians are one of the most common animals found within zooplankton assemblages. They play a very important role as filter feeders but are, unfortunately, inconsistently reported in the Antarctic literature. The present paper attempts to describe the zonal diversity of appendicularians and the main environmental factors influencing their communities in the Drake Passage. Samples were collected during Antarctic summer in 2009–2010. A total of eight species of larvaceans were identified. Fritillaria borealis was the species found in the highest numbers in almost the entire studied area, and was observed at all sampling stations. The distributions of other taxa were limited to specific hydrological zones and hydrological conditions. F. fraudax and Oikopleura gaussica were typical of the areas between the Polar Front and the Subantarctic Front zones, and their distributions were significantly correlated with temperature and salinity, likely making them good indicator species. The F. fusiformis distribution was strictly related to South American waters. In summary, temperature was the strongest environmental factor influencing the larvacean community structure in the Drake Passage, and we also found that testing environmental factors on larvaceans as a whole group did not give entirely reliable results.

Macrobenthic community of an estuarine tidal flat on the Amazon coast: spatial variations and presence of polychaetes tubes

The present study characterized the macrobenthic fauna found on a muddy-sandy tidal flat of the Amazon coast in areas with and without the presence of Diopatra cuprea (Bosc, 1802) (Onuphidae: Annelida) tubes. In addition, a brief review of records of D. cuprea on the Brazilian Amazon coast is presented. Samples were collected in February 2014 in two different areas: (1) an area in which D. cuprea tubes were present, and (2) a control area, in which worm tubes were absent. A total of 21 taxa were found, of which 10 were associated exclusively with D. cuprea tubes. Although richness did not vary significantly among areas, there were changes in the abundance and composition of species and trophic guilds. In the area with tubes, there was a higher abundance of filter-feeders and the presence of species adapted to consolidated and muddy substrates. Our results and those of other studies indicate that D. cuprea commonly presents low density in the Amazon coastal, and its tubes are typically scattered widely in the intertidal zone. The present findings add knowledge about the presence of the bioconstructor in coastal areas and reinforce the role of tube-building polychaetes as ecosystem engineers.

Diversity and Distribution of Sabellida (Annelida) under Protection Regimes

Sabellida are widespread, diverse and abundant in marine benthic habitats. Their distribution patterns on hard-bottom substrates are poorly studied so far. Little is known about the factors influencing their distribution, including the protection regimes that are known to affect assemblage diversity. We analyzed hard-bottom Sabellida at 1.5 and 5 m depths at the Torre Guaceto Marine Protected Area (MPA) (SE Italy) to describe diversity and distribution patterns, and to identify potential factors influencing their distribution. The Sabellida diversity varied significantly among stations and was higher at 5 m depth. No relation with the protection regime was found. Among environmental variables, only sedimentation appeared related, suggesting that local trophic features might have influenced the observed pattern. Among habitat formers, only the macroalga Halimeda tuna significantly explained part of the observed variation, probably due to its role as a basibiont for some Sabellida taxa. Other predictor variables of Sabellida distribution were the abundances of some invertebrate taxa, especially Syllidae and some filter feeders such as Sabellariida and Cirripedia, probably due to shared ecological requirements, rather than a direct effect on Sabellida distribution. The relation with the Syllidae remains obscure so far, albeit some kind of interaction (including predator/prey interactions) between these two taxa cannot be excluded. Sabellida should be taken into account when analyzing patterns of biodiversity of hard-bottom environments.