The Lesser Pacific Striped Octopus, Octopus chierchiae: An Emerging Laboratory Model

Cephalopods have the potential to become useful experimental models in various fields of science, particularly in neuroscience, physiology, and behavior. Their complex nervous systems, intricate color- and texture-changing body patterns, and problem-solving abilities have attracted the attention of the biological research community, while the high growth rates and short life cycles of some species render them suitable for laboratory culture. Octopus chierchiae is a small octopus native to the central Pacific coast of North America whose predictable reproduction, short time to maturity, small adult size, and ability to lay multiple egg clutches (iteroparity) make this species ideally suited to laboratory culture. Here we describe novel methods for multigenerational culture of O. chierchiae, with emphasis on enclosure designs, feeding regimes, and breeding management. O. chierchiae bred in the laboratory grow from a 3.5 mm mantle length at hatching to an adult mantle length of approximately 20–30 mm in 250–300 days, with 15 and 14% survivorship to over 400 days of age in first and second generations, respectively. O. chierchiae sexually matures at around 6 months of age and, unlike most octopus species, can lay multiple clutches of large, direct-developing eggs every ∼30–90 days. Based on these results, we propose that O. chierchiae possesses both the practical and biological features needed for a model octopus that can be cultured repeatedly to address a wide range of biological questions.

Sexual dimorphism and biology of the large deepwater mastigoteuthid squid Idioteuthis cordiformis (Cephalopoda, Mastigoteuthidae) off Tasmania, Australia

This study provided biological information on 146 specimens of the poorly known deepwater mastigoteuthid squid Idioteuthis cordiformis. Mantle length ranged from 200–500 mm for males and 270–702 mm for females. The largest female weighed just under 12 kg. The majority of males were mature and all females were immature. The fins were larger and thicker than the mantle. Mantle weight of males and females was 44.8% and 55.2% of fin weight, respectively, and were significantly different. There was a significant sex effect on mantle length, total weight, mantle weight and fin weight, with females having greater values in all categories. There was a small season effect for mantle weight and fin weight. There was little ingested prey material except fluid and oil in the caecum that was typically bright orange or red. Total fluid volume ranged from 23–230 ml and 20–550 ml for males and females, respectively. The per cent oil component of total fluids in the caecum ranged from 6.9–50% and 10.8–50% for males and females, respectively, with no significant difference in per cent oil between males and females. There was a significant positive relationship between total weight and oil volume for females, and for males and females combined. The function of the oil is uncertain. While this study provided information on sex differences in the body size, sexual dimorphism and caecum oil content, information is still incomplete regarding reproduction due to the lack of any mature females captured in this study.

Vancouver B and C periprosthetic fractures around the cemented Exeter Stem: sex is associate with fracture pattern

Introduction The aim of this study was to identify factors associated with the level of periprosthetic fracture involving a cemented polished tapered stem: Vancouver B or Vancouver C. Methods A retrospective cohort study of 181 unilateral periprosthetic fractures involving Exeter stems was assessed by three observers (mean age 78.5, range 39–103; mean BMI 27.1, 17–39; 97 (54%) male). Patient demographics, deprivation scores, BMI and time since primary prosthesis were recorded. Femoral diameter, femoral cortical thickness, Dorr classification and distal cement mantle length were measured from calibrated radiographs. Interobserver reliability was calculated using intraclass correlation coefficients (ICCs). Univariate and multivariate analysis was performed to identify associations with Vancouver B or C fractures. Results 160/181 (88%) Vancouver B and 21/181 (12%) Vancouver C-level fractures occurred at a mean of 5.9 ± 5.4 years (0.2–26.5) following primary surgery. Radiographic measurements demonstrated excellent agreement (ICC > 0.8, p < 0.001). Mortality was significantly higher following Vancouver C compared to B fractures: 90 day 14/160 Vs 5/21 (p = 0.05); 1 year 29/160 Vs 8/21 (p = 0.03). Univariate analysis demonstrated that Vancouver C fractures were associated with female sex, bisphosphonate use, cortical bone thickness, and distal cement mantle length (p < 0.05). On multivariate analysis, only female sex was an independent predictor of Vancouver C-level fractures (R2 =0.354, p = 0.005). Conclusion Most PFFs involving the Exeter stem design are Vancouver B-type fractures and appear to be independent of osteoporosis. In contrast, Vancouver C periprosthetic fractures display typical fragility fracture characteristics and are associated with female sex, thinner femoral cortices, longer distal cement mantles and high mortality.

The lesser Pacific striped octopus, Octopus chierchiae: an emerging laboratory model for the study of octopuses

Cephalopods have the potential to become useful experimental models in various fields of science, particularly in neuroscience, physiology, and behavior. Their complex nervous systems, intricate color- and texture-changing body patterns, and problem-solving abilities have attracted the attention of the biological research community, while the high growth rates and short life cycles of some species render them suitable for laboratory culture. Octopus chierchiae is a small octopus native to the central Pacific coast of North America whose predictable reproduction, short time to maturity, small adult size, and ability to lay multiple egg clutches (iteroparity) make this species ideally suited to laboratory culture. Here we describe novel methods for culture of O. chierchiae, with emphasis on enclosure designs, feeding regimes, and breeding management. Our results demonstrate the feasibility of multigenerational culture of O. chierchiae. Specifically, O. chierchiae bred in the laboratory grows from a 3.5-millimeter mantle length at hatching to an adult mantle length of approximately 20-30 millimeters in 250-300 days, with 14-15% survivorship to over 400 days of age in first and second generations. O. chierchiae sexually matures at around an estimated six months of age and, unlike most octopus species, can lay multiple clutches of eggs, approximately every 30-90 days. Eggs are large and hatchlings emerge as direct developing octopuses. Based on these results, we propose that O. chierchiae possesses both the practical and biological features needed for a model octopus that can be cultured repeatedly to address a wide range of fundamental biological questions.

Growth rates of the chokka squid Loligo reynaudii d’Orbigny, 1845 (Cephalopoda: Myopsida: Loliginidae) off South Africa, investigated over two years

Growth of adult chokka squid Loligo reynaudii d’Orbigny was modelled using mantle length and age data derived from samples collected over two years (2003 and 2004) from a single, large cohort of mature and spawning squid. A total of 588 statoliths were examined (310 males, 278 females) from individuals of 71–425 mm mantle length (ML). The maximum size of chokka squid was 425 mm ML for males and 263 mm ML for females. The Francis Growth Model and Linear Growth model were selected for further analysis from six models considered. Males and females attain similar ages, although mantle length-based daily growth rates ranged from 0.75 to 1.02 (0.88 quantile _50) mm/day for males and 0.32–0.45 (0.38 quantile _50) mm/day for females, explaining the sexual dimorphism apparent in the sizes of individuals of this species.

Hubungan Panjang Berat Dan Faktor Kondisi Loligo chinensis yang Didaratkan di TPI Tambak Lorok Semarang

Loligo chinensis merupakan salah satu jenis cumi-cumi yang memiliki nilai ekonomis penting di TPI Tambak Lorok Semarang. Produksi cumi-cumi merupakan hasil tangkapan dari alam, upaya penangkapan yang semakin tinggi dapat menyebabkan penurunan stok sumberdaya cumi-cumi. Tujuan penelitian ini adalah untuk mengetahui aspek biologi L.chinensis yang ada di Tambak Lorok yang meliputi hubungan panjang berat, faktor kondisi, dan pola pertumbuhan. Penelitian ini dilaksanakan pada bulan Juni-Juli 2020. Analisis data yang digunakan dalam penelitian adalah regresi linier sederhana dari log PM (panjang mantel) dan log W (weight) untuk mengetahui hubungan panjang beratnya. Nilai hubungan panjang berat L.chinensis mempunyai persamaan W = 0,00048L2,4921 untuk keseluruhan sampel, W = 3,237L0,84 pada betina dan W = 3,29L0,827 pada jantan dengan nilai slope (b) 2,4921; 0,84; dan 0,827. Nilai slope tersebut menunjukkan bahwa pertumbuhan L.chinensis bersifat alometrik negatif. Nilai faktor kondisi (Kn) = 1,064 pada keseluruhan sampel, Kn = 1,713 pada betina dan Kn = 1,63 pada jantan, nilai tersebut menunjukkan spesies ini tergolong memiliki badan yang kurus. Pertumbuhan panjang mantel (PM) L.chinensis tumbuh lebih lambat dibanding organ tubuh lain, kecuali terhadap berat tubuhnya. Loligo chinensis is one type of squid that has economic value crucial in the Tambak Lorok Semarang. Squid production mainly comes from nature, high fishing effort can cause a decrease in squid resource stock. The purpose of this study is to know the biological aspect L.chinensis in the Tambak Lorok include long weight relationships, condition factors, and the quality of alometry growth. The study was carried out in June-July 2020. The data analysis used is simple linear regression from the PM’s log (mantle length) and log W (weight) to know the relationship of its weight length. The relationship value between total length and total weight of L.chinensis has a W = 0,00048L2,4921 equation for the entire sample, W = 3,237L0,84 in the female and W = 3,29L0,827 in the male with slope (b) 2,4921; 0,84; and 0,827. Value slope shows the growths L.chinensis is negative alometrice. The value of the condition factor (Kn) = 1,064 in the entire sample, Kn = 1,713 in the female and Kn = 1,63 in the male. The value suggests that the species is thick-skinned. The growth of the mantle length (PM) of L.chinensis grows slower than other organs of the body, except for its total weight.

Redescriptions of two species of Sepia (Cephalopoda: Sepiidae) from South African waters: Sepia robsoni (Massy, 1927) and S. faurei Roeleveld, 1972

Two species of cuttlefish: Sepia robsoni (Massy) and Sepia faurei Roeleveld, are redescribed based on sexually mature males and females of both species. They were previously known only from their holotypes: male and female, respectively. They belong to a distinct group of small-sized sepiids, all near-endemics of southern African waters. The knowledge of the systematics and biology of this group is still limited despite the long time since the first description (1875). This is because, inter alia, of their small size: not larger than 4 cm mantle length at maturity. Twenty-one individuals of S. robsoni described here were scattered from Port Nolloth area to the Tsitsikamma coast (bottom depth <37–449 m). Eight known individuals of S. faurei came from the eastern Agulhas Bank (bottom depth 116–184 m). S. robsoni can be identified by extremely thinly calcified cuttlebone (transparent); smooth skin of dorsal mantle and head; tips of first pair of arms thick, finger-like, devoid of suckers. S. faurei can be distinguished by the following combination of characters: thick, heavily calcified cuttlebone but with flat and fused inner cone; skin of dorsal mantle and head very densely covered by characteristic warts; thin, whip-like tips of first pair of arms devoid of suckers. All described specimens of both species are deposited in the South African Institute of Aquatic Biodiversity (SAIAB) and in Iziko, South African Museum (SAMC).

Morphological comparison between Doryteuthis pleii and D. sanpaulensis (Cephalopoda, Myopsida, Loliginidae) from Brazil

The distinction of squid species in the genus Doryteuthis is not easy due to their morphological similarity, lack of conspicuous specific characters, and overlap geographical occurrence. This difficulty has leading to an almost exclusive molecular approach, and a premature neglect of the morpho-anatomy. To emphasize that the squid phenotypic features can be useful to identify, as well as to perform any comparative analyses (such as taxonomy and phylogeny), two close species were selected as outset. Doryteuthis pleii and D. sanpaulensis are common sympatric squids in Brazilian waters, commonly used in fisheries, not so difficult to distinguish by external features of the adult specimens. The samples were analyzed from biometric data to dissections, and the found most expressive characters to distinguish them are the mantle-fin ratio; morphology of the tentacle club, its ratio compared to the mantle length; hectocotylus morphology and nidamental gland morphology.

Migratory patterns, vertical distributions and diets of Abralia veranyi and Abraliopsis morisii (Cephalopoda: Enoploteuthidae) in the eastern North Atlantic

Abralia veranyi and Abraliopsis morisii were the most abundant cephalopods caught during epipelagic and mesopelagic surveys off the Canary Islands and accounted for 26% and 35% of the cephalopod catch, respectively. Diel vertical migration patterns were observed in both species. At night, A. veranyi was recorded at depths as shallow as 38–90 m, whereas Abraliopsis morisii occurred at depths of 98–219 m. As individuals grow in mantle length, their diet changes substantially. Abraliopsis morisii showed ontogenetic shifts at 22.9 mm and 35.3 mm dorsal mantle length (DML), while A. veranyi showed ontogenetic shifts at 20.5 mm and 30.9 mm DML. Prior to the first ontogenic shift, both species fed mainly on copepods and mysids. After this shift they fed on larger prey, such as decapods and fish; the diets of larger individuals also contained cephalopods.

KAJIAN BIOLOGI PERIKANAN PADA CUMI – CUMI Photololigo duvaucelii (d’Orbigny, 1835) YANG DIDARATKAN DI TPI TAMBAK LOROK SEMARANG Study on Fisheries Biology of Indian Squid (Photololigo duvaucelii d’Orbigny, 1835) in TPI Tambak Lorok Semarang

ABSTRAK Photololigo duvaucelii merupakan salah satu jenis cumi – cumi yang memiliki nilai ekonomis penting di TPI Tambak Lorok Semarang. Produksi cumi – cumi merupakan hasil tangkapan dari alam, upaya penangkapan yang semakin tinggi dapat menyebabkan penurunan stok sumberdaya cumi – cumi. Perlu adanya kegiatan yang dapat melestarikan sumberdaya agar tetap berkelanjutan. Tujuan penelitian ini adalah untuk mengetahui aspek biologi P. duvaucelii di Tambak Lorok yang meliputi hubungan panjang berat, faktor kondisi, tingkat kematangan gonad, indeks kematangan gonad dan karakteristik pertumbuhan alometri. Penelitian ini dilaksanakan pada bulan April – Mei 2018. Metode pengambilan sampel yang digunakan dalam penelitian ini adalah random sampling. Analisis data yang digunakan adalah regresi linier sederhana dari log ML(mantle length) dan log W (weight) umtuk mengetahui hubungan panjang beratnya. Nilai hubungan panjang berat P. duvaucelii mempunyai persamaan W = 0,024L1,580pada jantan dan W = 0,003L2,043 pada betina dengan nilai slope (b) 1,580 dan 2,043. Nilai slope tersebut menunjukkan bahwa pertumbuhan P. duvaucelii bersifat allometrik negatif. Nilai faktor kondisi (Kn) 1,037 pada jantan dan 1,063 pada betina, nilai tersebut menunjukkan spesies ini tergolong memiliki badan yang kurus. Pertumbuhan panjang mantel (ML) P. duvauceliitumbuh lebih lambat dibanding organ tubuh lain, kecuali terhadap berat tubuhnya. Tingkat kematangan gonad yang paling dominan dari P. duvaucelii jantan dan betina adalah TKG I (belum matang gonad). ABSTRACT Photololigo duvaucelii is one of the commercially important squid resources in TPI Tambak Lorok Semarang. Squid production mainly comes from nature, high fishing effort can cause a decrease in squid resource stock. Cacth in squid fisheries must be accompanied by other activity which to be able to increase population whilst maintain sustainable resources of the squid. This work aimed to study on fisheries biological which included length – weight relationship, condition factor, gonad maturity and gonado somatic index, also to learn morphometry characteristic of the P. duvaucelii in Tambak Lorok Semarang. This study was done in April – Mei 2018. Sample were collected using simple random sampling. A simple linear regression was used to describe the relationship between the log ML (mantle length) and the log W (weight). The length – weight relationship was expressed as W = 0,024L1,580 for male and W = 0,003L2,043 for female. Slope value (b) shows the growth of P. duvaucelii was negatively allometric. Conditon factor values in this research amounted to 1,037 for male and 1,063 for female, the range of this condition factor showed that the species has a flat body shape. Growth for mantle length (ML) of P. duvaucelii slower than other organs, except with the body weight. Maturity stages of P. duvauceliimale and female in this research dominated by maturity stages I (immature).