The larval morphology and the effects of sound frequencies on the settlement behaviour of the biofouling Bryozoan: Watersipora subatra

<p>Biofouling is a global issue, it is an ongoing expense for the maritime industry, billions of dollars are spent annually due to increased fuel consumption, research, maintenance and upkeep. The toxicity of anti-fouling paints is also a serious issue for the marine environment, because of the non-selective nature of the toxins they contain, they also affect non-target species, potentially harming local ecosystems. Biofouling acts as a vector for invasive species, allowing these species to spread world-wide, establish themselves in new ecosystems and potentially alter the biodiversity of the native flora and fauna. These issues with biofouling have seen an increase in research into the prevention of settlement of unwanted organisms on ship hulls; especially biofriendly, alternative options to toxic anti-fouling paints. A holistic approach to researching fouling species is vital in reducing and preventing biofouling, and with the increase in human activity in the marine environment, the effects of anthropogenic sounds on marine organisms is of growing interest. The potential effect of vessel noise on the larvae of bryozoan species has yet to be explored even though the Phylum Bryozoa is notorious for biofouling species. The morphology of larvae is also important in understanding the ecology of marine species, as various factors that influence the larval stage of a species can have latent effects in other life stages. Insight into the morphology of fouling larvae is important in understanding their life histories to develop more robust antifouling methods. Bryozoan larvae have a diverse range of morphological features to increase their survivability; a number of structures have been identified in aiding locomotion, phototaxis behaviour, suitable habitat exploration and metamorphosis. There is still a lot of speculation over the purpose of different structures and whether they have the potential to be used in other behaviours (such as auditory capabilities). This thesis focuses on the biofouling bryozoan species, Watersipora subatra, and examines their larval morphology and behaviour to better understand their early ecology and identify potential structures with auditory capabilities. SEM images of the larvae were used to identify a number of sensory organs that could potentially detect sound. A sound experiment was also conducted to test whether their larvae respond to different frequency levels (100Hz, 500Hz and 1000Hz). There was no significant difference in the settlement rate at the end of a 24-hour period between the different treatments. However, the larvae exposed to the lower frequency (100Hz) tended to be slower at settling in the initial 8 hours of the experiment, which is the optimal time to settle to increase post-settlement survivability. There is the potential for the larvae of bryozoan species to respond to sound frequencies, although more research is needed to fully elucidate their potential to sense sound and to potentially aid in developing a biofriendly, preventative solution to biofouling.</p>

The larval morphology and the effects of sound frequencies on the settlement behaviour of the biofouling Bryozoan: Watersipora subatra

<p>Biofouling is a global issue, it is an ongoing expense for the maritime industry, billions of dollars are spent annually due to increased fuel consumption, research, maintenance and upkeep. The toxicity of anti-fouling paints is also a serious issue for the marine environment, because of the non-selective nature of the toxins they contain, they also affect non-target species, potentially harming local ecosystems. Biofouling acts as a vector for invasive species, allowing these species to spread world-wide, establish themselves in new ecosystems and potentially alter the biodiversity of the native flora and fauna. These issues with biofouling have seen an increase in research into the prevention of settlement of unwanted organisms on ship hulls; especially biofriendly, alternative options to toxic anti-fouling paints. A holistic approach to researching fouling species is vital in reducing and preventing biofouling, and with the increase in human activity in the marine environment, the effects of anthropogenic sounds on marine organisms is of growing interest. The potential effect of vessel noise on the larvae of bryozoan species has yet to be explored even though the Phylum Bryozoa is notorious for biofouling species. The morphology of larvae is also important in understanding the ecology of marine species, as various factors that influence the larval stage of a species can have latent effects in other life stages. Insight into the morphology of fouling larvae is important in understanding their life histories to develop more robust antifouling methods. Bryozoan larvae have a diverse range of morphological features to increase their survivability; a number of structures have been identified in aiding locomotion, phototaxis behaviour, suitable habitat exploration and metamorphosis. There is still a lot of speculation over the purpose of different structures and whether they have the potential to be used in other behaviours (such as auditory capabilities). This thesis focuses on the biofouling bryozoan species, Watersipora subatra, and examines their larval morphology and behaviour to better understand their early ecology and identify potential structures with auditory capabilities. SEM images of the larvae were used to identify a number of sensory organs that could potentially detect sound. A sound experiment was also conducted to test whether their larvae respond to different frequency levels (100Hz, 500Hz and 1000Hz). There was no significant difference in the settlement rate at the end of a 24-hour period between the different treatments. However, the larvae exposed to the lower frequency (100Hz) tended to be slower at settling in the initial 8 hours of the experiment, which is the optimal time to settle to increase post-settlement survivability. There is the potential for the larvae of bryozoan species to respond to sound frequencies, although more research is needed to fully elucidate their potential to sense sound and to potentially aid in developing a biofriendly, preventative solution to biofouling.</p>

Description of larval morphology and phylogenetic relationships of Heterotemna tenuicornis (Silphidae)

Providing clear and detailed morphological descriptions of endemic species in limited areas enables new knowledge of their biology and ecology to be obtained through citizen science. This information can be further used for their protection. Our study presents the first morphological description of the larvae of all three instars of Heterotemna tenuicornis (Brullé, 1836), an endemic species of the Canary Islands that, together with H. britoi García & Pérez, 1996 and H. figurata (Brullé, 1839), belongs to the peculiar genus Heterotemna Wollaston, 1864. Furthermore, we present the first sequences of two mitochondrial genes (COI, 16S) obtained from larval specimens, and cross reference them with sequences from an adult specimen. Phylogenetic analysis of molecular data placed the genus Heterotemna within the genus Silpha Linnaeus, 1758, suggesting paraphyly of Silpha. In our study, we underline the importance of using a combination of morphological description and molecular data, that can be used for barcoding developmental stages which could not otherwise be definitely associated.

A review of the New Zealand Berosus (Coleoptera: Hydrophilidae) with descriptions of three new species

The New Zealand species of the water scavenger beetle genus Berosus Leach, 1817 are reviewed based on freshly collected material and museum specimens. Four species are recognized: Berosus pallidipennis (Sharp, 1884) widespread in the North and South Islands, B. muellerorum sp. nov. from the eastern part of the North Island, and B. halasi sp. nov. and B. maru sp. nov., both endemic to central part of South Island. The synonymy of B. mergus Broun, 1886 with B. pallidipennis is confirmed and lectotypes for both taxa are designated. The larval morphology of B. pallidipennis and B. muellerorum is briefly discussed. Distributional data of all species are reported and illustrated, indicating a noticeable lack of Berosus species in the northern part of North Island and in Stewart Island and the presence of two rare species in the South Island, east of Southern Alps. An identification key to New Zealand species of the genus is provided

The first zoeal stage of the yellow land crab Johngarthia lagostoma (Milne Edwards, 1837) (Decapoda: Brachyura: Gecarcinidae)

The objective of this paper is to describe and illustrate the first zoeal stage of the largest land crab of the Tropical Atlantic, Johngarthia lagostoma (Milne Edwards, 1837) (Brachyura: Gecarcinidae). A larval description of J. lagostoma was previously not available. Larvae were obtained from ovigerous females on Rocas Atoll and Fernando de Noronha Archipelago, Brazil. Twenty larvae were randomly chosen to be dissected and described in detail, while 40 others (20 larvae from each island) were measured only. The published description of the congener J. planatus (Stimpson, 1860) larvae was used for a comparison of larval morphology. Some morphological differences between the first zoeal stage of these two species were: The absence or presence of a simple shorter seta on antennule, number of the minute terminal spines on the antenna, setation of the coxal endite of the maxilla, exopod unsegmented of the first and second maxilliped, and a single mid-dorsal seta on first pleonite. These results and differences observed between these species can assist in studies on phylogenetic relationships within the Family Gecarcinidae MacLeay, 1838, as well as in the identification of the larvae of J. Lagostoma in plankton samples from the tropical Atlantic.

Toward a Stable Global Noctuidae (Lepidoptera) Taxonomy

Noctuidae are one of the world’s most diverse, ecologically successful, and economically important animal lineages with over 12,000 species in ~1,150 genera. We inferred a phylogeny using eight protein-coding genes for the global fauna, greatly expanding upon previous attempts to stabilize Noctuidae higher classification by sampling 341 genera (nearly half represented by their type species) representing 70/76 widely recognized family-group taxa: 20/21 subfamilies, 32/35 tribes, and 18/20 subtribes. We evaluated 17 subfamily-level taxa in detail, discussing adult and larval morphology, life histories, and taxonomic implications of our results. We significantly alter concepts of Acontiinae, Condicinae, Eustrotiinae, Metoponiinae, and Stiriinae. Our results supported recognition of two new subfamilies: Cobubathinae Wagner & Keegan, 2021 subf. nov. and Cropiinae Keegan & Wagner, 2021 subf. nov. Other nomenclatural changes we made are as follows. We moved: ‘Acontia’ viridifera (Hampson, 1910), ‘Azenia’ virida Barnes and McDunnough, 1916, Aleptinoides, Austrazenia, Chalcoecia, Megalodes, and Trogotorna to Chamaecleini in Acontiinae; Apaustis to, and reinstated Emmelia as a valid genus in Acontiinae; Allophyes and Meganephria to Cuculliinae; ‘Plagiomimicus’ navia (Harvey, 1875), Airamia, Alvaradoia, Hypoperigea, Neotarache, and Mesotrosta to Condicinae; Axenus, Azenia, Metaponpneumata, Sexserrata, and Tristyla to Metoponiinae; ‘Paramiana’ canoa (Barnes, 1907) to Noctuinae; Aucha, Cobubatha, and Tripudia to Cobubathinae; Anycteola and Supralathosea to Oncocnemidinae; Cropia to Cropiinae; Desmoloma to Dyopsinae; Eviridemas and Gloanna to Bryophilinae; Fota and Stilbia to Stiriinae; and Copibryophila, Homolagoa, and Tyta to Noctuidae incertae sedis. We conclude with discussion of instances where current understanding of noctuid biogeography and life histories were changed by our results.