Behavior, neurobiology, and behavioral ecology (session summary; all summaries compiled by R.A. Wahle)

Published versio

ICWL session: Behavior, neurobiology, and behavioral ecology

http://www.fish.wa.gov.au/Documents/rock_lobster/the_lobster_newsletter/lobster_newsletter_v30_no2.pdfhttp://www.fish.wa.gov.au/Documents/rock_lobster/the_lobster_newsletter/lobster_newsletter_v30_no2.pdfPublished versio

Survival and growth of early-juvenile American lobsters Homarus americanus through their 1st season while fed diets of mesoplankton, microplankton, and frozen brine shrimp

American lobsters Homarus america.nus were fed diets of mesoplankton in filtered seawater, meso/ microplankton combination in filtered seawater, and frozen brine shrimp in both filtered and unfiltered seawater to determine if mesoplankton diets could sustain survival and growth throughout most of the first year of molts and if smaller zooplankters and phytoplankton in the mesol microplankton diet could be utilized as food and could sustain survival in periods of low food supply. At the beginning of the experiment, there were no significant differences in either carapace length or weight between the groups of sibling lobsters. Lobsters fed mesoplankton had high survival (80%) and significant increases in both carapace length and weight, although they weighed less at Stage IX than those fed frozen brine shrimp in unfiltered seawater. Lobsters fed frozen brine shrimp in filtered seawater had low survival (15%), but did not differ significantly at Stage IX from those fed mesoplankton in terms of both carapace length and weight. Lobsters fed brine shrimp in unfiltered seawater had high survival rates (95%) and weighed nearly twice as much at Stage IX than both the brine shrimp-fed lobsters in filtered seawater and the mesoplankton-fed lobsters; however, none of these three surviving groups differed significantly in carapace length at Stage IX. Intermolt periods for the three surviving groups were not significantly different until the molt between Stage VIII and IX when the mesoplankton-fed lobsters took nearly twice as long to molt as either of the brine shrimp-fed groups. Lobsters fed mesolmicroplankton did not molt out of Stage V and died within 36 days of the 107-day experiment. These results indicate that mesoplankton diets promote growth and survival of lobsters throughout most of their first season of molting and that larger planktonic organisms may contain essential nutritional requirements not met by brine shrimp alone. However, the meso/microplankton diet, consisting mostly of diatoms, does not provide sufficient nutrition for survival dwing periods of starvation

The international Conference and Workshop on Lobster Biology and Management celebrates its 40th year!

[PREFACE] Once again, the International Conference and Workshop on Lobster Biology and Management (ICWL) visited the shores of the northwest Atlantic Ocean, some of the most productive lobster grounds on the planet. The University of Maine and Boston University welcomed 257 attendees from 14 countries to Portland, Maine, from June 4 to 9, 2017. Hosted twice earlier in Atlantic Canada, this 11th ICWL was the first time in the US Northeast, and fittingly, in the state nearly synonymous with lobster! The Holiday Inn-by-the-Bay in downtown Portland proved to be the perfect central venue to run our science sessions and socials over the course of the week, and to savor the city’s many restaurants and waterfront activities overlooking Casco Bay. This meeting also marked the ICWL’s 40th anniversary. In 1977, Bruce Phillips (Western Australia Fisheries) and J Stanley Cobb (University of Rhode Island) organized that first event in Perth, Australia, gathering a core group of 35 participants from six countries. Their vision was to assemble scientists, fishery managers, and industry members with common interests in lobsters of all stripes. The first meeting resulted in the landmark two-volume set, The Biology and Management of Lobsters, published in 1980. Its 18 peer-reviewed chapters comprise the first comprehensive review of information on spiny, clawed, and slipper lobsters around the world. It also identified knowledge gaps that spurred new and innovative research on lobster biology and ecology that has informed the management of lobster fisheries in the ensuing years. We stand on the shoulders of these originals who gave us a rich legacy of scientific contributions and mentored a virtual army of students who have made significant contributions in their own right.Published versio

The slipper lobster, Scyllarides latus, uses apatite and fluorapatite to protect its sensory organules

The cuticle of arthropods has been intensely studied not only to better understand the properties of a natural composite material, but also to understand how structural properties and mineral contributions to this composite offer a durable protective covering from predator and microbial attack. Thus far, most marine cuticular studies have focused on the American lobster, Homarus americanus, or several crab species, but have largely ignored other types of lobsters, such as spiny or slipper lobsters that have exoskeletons differing in both structural properties (i.e., amount of trabeculae present in pits and spines) and resistance to structural failure. Using an electron microprobe, we analyzed various segments of the exoskeleton of the Mediterranean slipper lobster, Scyllarides latus, to determine the mineral content in discrete domains of cuticle. EMP analysis determined that the cuticle of S. latus is similar to that of H. americanus in that it contains carbonate apatite in canal linings and in the areas surrounding sensory organules (setae). The slipper lobster also uses a fluorapatite mineral that further adds strength to the shell. Results will be discussed in the context of what this means for defense against attack and differences in environmental water chemistry and resilience to climate change

ICWL celebrates its 40th year!

http://www.fish.wa.gov.au/Documents/rock_lobster/the_lobster_newsletter/lobster_newsletter_v30_no2.pdfhttp://www.fish.wa.gov.au/Documents/rock_lobster/the_lobster_newsletter/lobster_newsletter_v30_no2.pdfPublished versio

Descriptions of the setae on the pereiopods of scyllarid lobsters, Scyllarides aequinoctialis, S. latus, and S. nodifer, with observations on the feeding sequence during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster feeding have remained largely unexplored. Using Scanning Electron Microscopy (SEM), the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters: Scyllarides aequinoctialis, S. latus, and S. nodifer. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in S. aequinoctialis only. Comparisons among species demonstrate that S. nodifer bears the same setae and setal pattern as S. latus, but S. aequinoctialis differs. The setal patterns of slipper lobsters contrast with those of nephropid and palinurid lobsters, likely due to the more rigorous use of the pereiopods in accessing their food. Feeding sequences of S. aequinoctialis on bivalves were videotaped, analyzed as Markovian chains, and showed a complex suite of behaviors involving contact chemoreception by the antennules as part of an initial assessment of food items, followed by mouthpart and leg probing, and eventual wedging behavior as previously described for S. squammosus. Feeding sequences of S. latus on gastropods and bivalves also demonstrate extensive use of the pereiopods (instead of the mouthparts) first to pry these prey items from the substrate and then to remove the foot. Use of antennules for food assessment and recruitment of many of the perieopods for food handling with minimal use of mouthparts also contrasts with the feeding sequences typical of nephropid and palinurid lobsters and may be an important adaptation

A noninvasive method for in situ determination of mating success in female American lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female's seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George's Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations

The Joker effect: cooperation driven by destructive agents

Understanding the emergence of cooperation is a central issue in evolutionary game theory. The hardest setup for the attainment of cooperation in a population of individuals is the Public Goods game in which cooperative agents generate a common good at their own expenses, while defectors "free-ride" this good. Eventually this causes the exhaustion of the good, a situation which is bad for everybody. Previous results have shown that introducing reputation, allowing for volunteer participation, punishing defectors, rewarding cooperators or structuring agents, can enhance cooperation. Here we present a model which shows how the introduction of rare, malicious agents -that we term jokers- performing just destructive actions on the other agents induce bursts of cooperation. The appearance of jokers promotes a rock-paper-scissors dynamics, where jokers outbeat defectors and cooperators outperform jokers, which are subsequently invaded by defectors. Thus, paradoxically, the existence of destructive agents acting indiscriminately promotes cooperation.Comment: Accepted for publication in the Journal of Theoretical Biology (JTB

The 11th International Conference and Workshop on Lobster Biology and Management

As large, charismatic species, lobsters of all stripes often find themselves at the center of scientific research and in the media spotlight. Lobster fisheries are important economic drivers of coastal communities around the world. Indeed, lobsters are poster children of a marine environment increasingly under the pressures of human exploitation and environmental change. The 200+ abstracts in this program reflect the activity of a vibrant international community of researchers and industry members striving to understand what makes lobsters tick and keep their fisheries sustainable