Heavy metal pollution index calculation in geochemistry assessment: a case study on Playa Las Petroleras.

This work is aimed to assess potential risk associated with the presence of metals and metalloids in soil at "Playa Las Petroleras" sector, located in Antofagasta (Chile). The zone under study has been affected by four oil spill events. This sector is located in an urban area by the sea. So, it has a great social and environmental relevance. The concentrations of 15 elements in soil samples were assessed, four of them presenting potential ecological risk: As, Co, Cu, and Pb. Nine pollution indices were applied to data: four single pollution indices and five integrated pollution indices to assess soil pollution. The single pollution indices show that the site bears potential ecological and environmental risk due to the presence of Cu, the site being classified as highly contaminated owing to a severe enrichment of this metal. For Co, all the indices allow classifying the site as little or uncontaminated, while the level of As and Pb pollution could be considered as ranging from uncontaminated to moderately contaminated. The integrated pollution indices show that average concentrations are highly contaminated mainly owing to the presence of Cu.

Characteristic curve modeling of plant species behavior in soils with heavy metals.

Many vegetal species can accumulate great amounts of metallic elements in their tissues. For this reason, they are called metal hyperaccumulators. An indicator of great interest in environmental sciences is the bioconcentration factor because it is recognized for establishing the potential accumulation of chemicals in organisms. Particularly in soil phytoremediation processes, it measures the capacity of a certain plant to capture metals, in terms of soil concentration. According to their behavior, four types of plants can be distinguished regarding soil concentration increase: indicator, excluder, accumulator, and hyperaccumulator. This study proposes a new model to categorize plants according to their behavior related to soil concentration increase, using several characteristic curves obtained from 1288 experimental measurements collected from different bibliographic sources. The metals analyzed were Cu, Fe, Pb, and Zn. The proposed model is obtained through linear regression and nonlinear transformations to model the expected behavior of plants in high concentration conditions. In particular, the basic equation of the model has three key components to represent the expected concentration in the plant root given the final soil concentration level, the type of species, and specific metal: a linear factor that determines the growth for low concentration values, an exponential factor that determines its decrease for high concentration values, and a logarithmic factor that limits the maximum value that can be reached in practice and influences the decay for high concentration values. After fitting the experimental data using linear regression, the proposed model has a 0.084 R2 determination coefficient and all of its parameters are considered significant. Furthermore, it shows that 60 of the 257 species assessed behave as accumulators and 10 of them as hyperaccumulators. The main contribution of this model is its ability to handle soils with high concentrations, where it would be hard for plants to achieve concentrations similar to or higher than the substrate containing them. Thus, the conventional criterion of the bioconcentration factor would incorrectly categorize a plant as an excluder. In contrast, this new model allows assessing plant effectiveness in a phytoremediation process of highly concentrated affected sites, such as mine tailings.

An extension of the characteristic curve model of plant species behavior in heavy metal soils.

This article proposes a mathematical model to characterize phytoremediation processes in soils contaminated with heavy metals. In particular, the proposed model constructs characteristic curves for the concentrations of several metals (As, Cd, Cu, Fe, Pb, Sb, and Zn) in soils and plants based on the experimental data retrieved from several bibliographical sources comprising 305 vegetal species. The proposed model is an extension of previous models of characteristic curves in phytoremediation processes developed by Lam et al. for root measurements using the bioconcentration factor. However, the proposed model extends this approach to consider roots, as well as aerial parts and shoots of the plant, while at the same time providing a less complex mathematical formula compared to the original. The final model shows an adjusted R2 of 0.712, and all its parameters are considered statistically significant. The model may be used to assess samples from a given plant species to identify its potential as an accumulator in the context of soil phytoremediation processes. Furthermore, a simplified version of the model was constructed using an approximation to provide an easy-to-compute alternative that is valid for concentrations below 37,000 mg/kg. This simplified model shows results similar to the original model for concentrations below this threshold and it uses an adjusted factor defined as [Formula: see text] that must be compared with a threshold depending on the metal, type of measurement, and target (e.g., accumulator or hyperaccumulator). The full model construction shows that 90 out of the 305 species assessed have a potential behavior as accumulators and 10 of them as hyperaccumulators. Finally, out of the 1405 experimental measurements, 1177 were shown to be accumulators or hyperaccumulators. In particular, 85% of the results coincide with the reported values, thus validating the proposed model.

Fellows perspective of HPB training in Latin America.

BACKGROUND: Currently, no standards for HPB training exist in Latin America. The aim of this work is to evaluate fellows' experience of HPB training and the areas of opportunity to improve. METHODS: A 35 points survey was developed and distributed among fellows from dedicated HPB training programs in Latin America. The survey was applied by direct phone call (37%) or web based (63%), to fellows graduated between 2010 and 2014, from 7 different programs. RESULTS: Thirty-nine fellows from Argentina, Brazil, Chile and México were considered with a response rate of 82% (32/39). Most fellows (90%) shared cases with more than one co-fellow. Scrubbing with chief residents ocurred to 60% of fellows; only 14% of fellows noted having a primary surgeon role in more than 70% of cases. Median number of major hepatectomies during training was 15 (1-100), Whipple procedures 6 (1-40), and major bile duct repair 20 (1-80). Limited funding was the main reason to avoid HPB programs outside the country of origin. CONCLUSION: HPB training in Latin America requires more operative volume and autonomy. Financial burden is the main limitation to pursue training overseas. A multinational fellowship that takes advantage of each center may overcome differences in volume and type of cases.

A phylum-wide survey reveals multiple independent gains of head regeneration in Nemertea.

Animals vary widely in their ability to regenerate, suggesting that regenerative ability has a rich evolutionary history. However, our understanding of this history remains limited because regenerative ability has only been evaluated in a tiny fraction of species. Available comparative regeneration studies have identified losses of regenerative ability, yet clear documentation of gains is lacking. We assessed ability to regenerate heads and tails either through our own experiments or from literature reports for 35 species of Nemertea spanning the diversity of the phylum, including representatives of 10 families and all three orders. We generated a phylogenetic framework using sequence data to reconstruct the evolutionary history of head and tail regenerative ability across the phylum and found that all evaluated species can remake a posterior end but surprisingly few could regenerate a complete head. Our analysis reconstructs a nemertean ancestor unable to regenerate a head and indicates independent gains of head regenerative ability in at least four separate lineages, with one of these gains taking place as recently as the last 10-15 Myr. Our study highlights nemerteans as a valuable group for studying evolution of regeneration and identifying mechanisms associated with repeated gains of regenerative ability.

Indocyanine green fluorescence imaging to evaluate graft perfusion during liver transplantation.

BACKGROUND: Primary graft dysfunction (PGD) is a leading cause of graft loss after liver transplantation. There is no reliable method to anticipate this complication intraoperatively. Indocyanine green (ICG) fluorescence imaging is a technique used in hepatobiliary surgery for detection of liver malignancies, but has never been reported in the setting of liver transplantation (LT) for function assessment. We hypothesized that there could be an association between the type of fluorescence and the occurrence of PGD. METHODS: We retrospectively analyzed 72 patients who underwent LT at our center. An assessment of the liver graft with the ICG fluorescence technique was carried out. A classification comprising 3 types of fluorescence was created after evaluation of the recorded images. We assessed the relationship between the type of fluorescence and the occurrence of PGD. RESULTS: Crosstabulation analysis of the fluorescent types and occurrence of PGD yielded a statistically significant association (p = 0.002). Univariate analysis showed that an abnormal ICG fluorescence pattern was a risk factor for the occurrence of PGD after LT. CONCLUSIONS: Our findings suggest that there could be an association between ICG fluorescence imaging and graft function. This intraoperative tool could be useful to detect patients at risk of developing PGD after LT.

Interstage Assessment of Remnant Liver Function in ALPPS Using Hepatobiliary Scintigraphy: Prediction of Posthepatectomy Liver Failure and Introduction of the HIBA Index.

OBJECTIVE: The aim of this study was to evaluate interstage liver function in associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS) using hepatobiliary scintigraphy (HBS) and whether this may help to predict posthepatectomy liver failure (PHLF). BACKGROUND: ALPPS remains controversial given the high rate of liver-related mortality after stage 2. HBS combined with single photon emission computed tomography (SPECT) accurately estimates future liver remnant function and may be useful to predict PHLF. METHODS: Between 2011 and 2016, 20 of 39 patients (51.3%) underwent SPECT-HBS before ALPPS stage 2 for primary (n = 3) or secondary liver tumors (n = 17) at the Hospital Italiano de Buenos Aires (HIBA). PHLF was defined by the International Study Group of Liver Surgery criteria, 50-50 criteria, or peak bilirubin >7 mg/dL. Grade A PHLF was excluded, as it requires no change in clinical management. Receiver-operating characteristic curves were used to determine cutoff for HBS parameters. RESULTS: Interstagely, 3 HBS parameters differed significantly between patients with (n = 4) and without PHLF (n = 16) after stage 2. Among these, the HIBA-index best predicted PHLF, with a cutoff value of 15%. The risk of PHLF in patients with cutoff <15% was 80%, whereas no patient with cutoff ≥15% developed PHLF. CONCLUSIONS: Interstage HBS could help to predict clinically significant PHLF after ALPPS stage 2. An HIBA-index cutoff of 15% seemed to give the best diagnostic performance. Although further studies are needed to confirm our findings, the routine application of this noninvasive low-cost examination could facilitate decision-making in institutions performing ALPPS.

Risk Adjustment in ALPPS Is Associated With a Dramatic Decrease in Early Mortality and Morbidity.

OBJECTIVE: To longitudinally assess whether risk adjustment in Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) occurred over time and is associated with postoperative outcome. BACKGROUND: ALPPS is a novel 2-stage hepatectomy enabling resection of extensive hepatic tumors. ALPPS has been criticized for its high mortality, which is reported beyond accepted standards in liver surgery. Therefore, adjustments in patient selection and technique have been performed but have not yet been studied over time in relation to outcome. METHODS: ALPPS centers of the International ALPPS Registry having performed ≥10 cases over a period of ≥3 years were assessed for 90-day mortality and major interstage complications (≥3b) of the longitudinal study period from 2009 to 2015. The predicted prestage 1 and 2 mortality risks were calculated for each patient. In addition, questionnaires were sent to all centers exploring center-specific risk adjustment strategies. RESULTS: Among 437 patients from 16 centers, a shift in indications toward colorectal liver metastases from 53% to 77% and a reverse trend in biliary tumors from 24% to 9% were observed. Over time, 90-day mortality decreased from initially 17% to 4% in 2015 (P = 0.002). Similarly, major interstage complications decreased from 10% to 3% (P = 0.011). The reduction of 90-day mortality was independently associated with a risk adjustment in patient selection (P < 0.001; OR: 1.62; 95% CI: 1.36-1.93) and using less invasive techniques in stage-1 surgery (P = 0.019; OR: 0.39; 95% CI: 0.18-0.86). A survey indicated risk adjustment of patient selection in all centers and ALPPS technique in the majority (80%) of centers. CONCLUSIONS: Risk adjustment of patient selection and technique in ALPPS resulted in a continuous drop of early mortality and major postoperative morbidity, which has meanwhile reached standard outcome measures accepted for major liver surgery.

Intrahepatic cholangiojejunostomy for complex biliary stenosis after pediatric living-donor liver transplantation.

The treatment of biliary stenosis after pediatric LDLT is challenging. We describe an innovative technique of peripheral IHCJ for the treatment of patients with complex biliary stenosis after pediatric LDLT in whom percutaneous treatment failed. During surgery, the percutaneous biliary drainage is removed and a flexible metal stylet is introduced trough the tract. Subsequently, the most superficial aspect of the biliary tree is recognized by palpation of the stylet's round tip in the liver surface. The liver parenchyma is then transected until the bile duct is reached. A side-to-side anastomosis to the previous Roux-en-Y limb is performed over a silicone stent. Among 328 pediatric liver transplants performed between 1988 and 2015, 26 patients developed biliary stenosis. From nine patients requiring surgery, three patients who had received left lateral grafts from living-related donors due to biliary atresia were successfully treated with IHCJ. After a mean of 45.6 months, all patients are alive with normal liver morphological and function tests. The presented technique was a feasible and safe surgical option to treat selected pediatric recipients with complex biliary stenosis in whom percutaneous procedures or rehepaticojejunostomy were not possible, allowing complete resolution of cholestasis and thus avoiding liver retransplantation.

Inverting the ALPPS paradigm by minimizing first stage impact: the Mini-ALPPS technique.

PURPOSE: The current associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) approach is represented by an aggressive first surgical procedure followed by a shorter and less aggressive second procedure. This paradigm has been associated with high morbidity and mortality. Inverting the aggressiveness of the surgical stages might be beneficial in order to facilitate patient recovery during interval period. We propose a new technical paradigm for the ALPPS approach. METHODS: During the first stage, partial parenchymal transection combined with intraoperative portal vein embolization (PVE) was performed. Liver mobilization was kept at minimum while hilar plate or hilum dissection was strictly avoided. The completion surgery by means of the anterior approach was carried out once sufficient future liver remnant (FLR) hypertrophy and function were certified. RESULTS: We applied this technique in four patients (hepatocellular carcinoma in a cirrhotic liver = 1 and colorectal liver metastases = 3). The mean FLR hypertrophy was 62.6 % (range 49-79). All the four patients underwent the completion surgery with R0 margins, and neither one developed liver failure nor major complications. CONCLUSIONS: The technique proposed inverts the current ALPPS strategy, minimizing the first stage impact to promote rapid patient recovery and leaving the main surgical procedure for the second stage. The combination of evidence-based facts such as partial parenchymal transection, intraoperative PVE, and "non-touch" oncological rules was feasible and safe, allowing complete tumor resection in highly selected candidates with extensive liver disease.

Surgical strategies for restoring liver arterial perfusion in pancreatic resections.

BACKGROUND: Hepatic perfusion failure represents an important risk factor for severe complications and death after pancreatic resections. Arterial reconstruction could be required during pancreatic surgery because of tumor infiltration, benign strictures, or as a consequence of accidental arterial injury during dissection. All these situations can be faced with a certain frequency in high-volume pancreatic centers, where surgeons must be aware of the different alternatives to deal with these intricate scenarios. PURPOSE: We herein describe the preoperative surgical planning as well as different surgical strategies for the restoration of arterial perfusion of the liver in pancreatic resections. CONCLUSION: A thorough preoperative evaluation is essential for planning pancreatic surgery and preparing the surgeon and patient for potentially high complex procedures. The various therapeutic alternatives presented in this technical report might represent a good solution for selected patients with no other potentially curative option than surgery.

Associating liver partition and portal vein ligation for staged hepatectomy offers high oncological feasibility with adequate patient safety: a prospective study at a single center.

OBJECTIVE: To determine the safety, feasibility, and efficacy of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in a single high-volume hepatobiliary center. BACKGROUND: The ALPPS approach allows achieving resectability of liver malignancies by a rapid and large future liver remnant (FLR) hypertrophy. However, this proposal has been associated with high morbidity and mortality rates. METHODS: This was a single-cohort, prospective, observational study [NCT02164292]. Between June 2011 and April 2014, patients with liver malignancies considered unresectable due to an insufficient FLR who underwent ALPPS were included. RESULTS: Thirty patients were treated. Median age was 58.6 years (range = 35-81) and 19 patients were males (63%). In a median of 6 days (range = 4-67), the median FLR hypertrophy was 89.7% (range = 21-287). Twenty-nine patients completed the second stage (97% feasibility). Morbidity according to the Dindo-Clavien classification was 53% (grade ≥IIIa 43% and grade ≥IIIb 31%). The mortality rate was 6.6%. Total parenchymal transection was identified as an independent risk factor for complications (P = 0.049). There was not significant difference in terms of FLR hypertrophy between total or partial parenchymal transection (P = 0.45). Median hospital stay was 16 days (range = 11-62). The overall and disease-free survival at 1 year was 78% and 67% and at 2 years was 63% and 40%, respectively. CONCLUSIONS: This prospective study on the largest reported single-center experience shows that ALPPS has acceptable morbidity and mortality, together with a high oncological feasibility and hypertrophic efficacy. Partial parenchymal transection seems to reduce morbidity without negatively impacting FLR hypertrophy.

Postoperative complications at a university hospital: is there a difference between patients operated by supervised residents vs. trained surgeons?

BACKGROUND: The surgical residency system ensures supervised practices to progressively move from simple to complex surgical procedures. However, ethical dilemmas could arise if patient outcome is negatively affected by this learning methodology. The objective of this study was to evaluate whether the supervised participation of residents acting as operating surgeons influences the postoperative complication rate. METHODS: Surgeries performed between June 2010 and May 2011 were analyzed. The Dindo-Clavien classification was used to stratify the severity of complications. The complication rates of patients operated by supervised residents (SR) and trained surgeons (TS) were compared considering potential confounders related to the patient and surgical procedure. RESULTS: A total of 3697 consecutive surgical procedures were included. Age, gender, and American Society of Anesthesiologists (ASA) risk were not different between patients of both groups. The overall complication rate was 10.8 %, without significant differences between the SR and TS groups (9.8 vs. 11.4 %; P = 0.14). The severity of complications was similar in both groups. Multivariate analysis adjusted for confounders confirmed that resident participation was not an independent risk factor for complications (odds ratio 1.52; 95 % CI 0.79-2.92; P = 0.20). CONCLUSIONS: Supervised resident participation, as operating surgeon, does not negatively impact postoperative patient outcome. Residency training may therefore be considered as an ethical and safe learning methodology whenever implemented in the framework of an academic teaching hospital.

Rediscovery and redescription of Leodice laurillardi (Quatrefages, 1866) comb. nov. (Annelida: Eunicidae)-a rare European polychaete or just an overlooked species?

The eunicid polychaete, Eunice laurillardi Quatrefages, 1866, originally described from the central Mediterranean, has been discovered on the northern Iberian Peninsula, constituting the first report of the species since its original description. The new specimens are compared with the type collection and the species is redescribed. Furthermore, the species is assigned to the genus Leodice Savigny in Lamarck, 1818, based on information provided by re-examination of type material and the newly collected specimens. A summary of the complex taxonomic history of the species and a discussion of its current status are also provided.

Adjuvant chemotherapy is associated with better oncological outcomes after ALPPS for colorectal liver metastases.

ALPPS enables complete tumor resection in a shorter interval and a larger number of patients than classic two-stage hepatectomies. However, there is little evidence regarding long-term outcomes in patients with colorectal liver metastases (CLM). This study aims to evaluate the short and long-term outcomes of ALPPS in patients with CRM. Single-cohort, prospective, observational study. Patients with unresectable CLM due to insufficient liver remnant who underwent ALPPS between June 2011 and June 2021 were included. Of 32 patients treated, 21 were male (66%) and the median age was 56 years (range = 29-81). Both stages were completed in 30 patients (93.7%), with an R0 rate of 75% (24/32). Major morbidity was 37.5% and the mortality nil. Median overall survival (OS) and recurrence-free survival (RFS) were 28.1 and 8.8 months, respectively. The 1-3, and 5-year OS was 86%, 45%, and 21%, and RFS was 42%, 14%, and 14%, respectively. The only independent risk factor associated with poor RFS (5.7 vs 11.6 months; p = 0.038) and OS (15 vs 37 months; p = 0.009) was not receiving adjuvant chemotherapy. KRAS mutation was associated with worse OS from disease diagnosis (24.3 vs. 38.9 months; p = 0.025). ALPPS is associated with favorable oncological outcomes, comparable to traditional strategies to increase resectability in patients with CLM and high tumor burden. Our results suggest for the first time that adjuvant chemotherapy is independently associated with better short- and long-term outcomes after ALPPS. Selection of patients with KRAS mutations should be performed with caution, as this could affect oncological outcomes.

New surgical strategy to induce liver hypertrophy: role of MDCT-volumetry to monitor and predict liver growth.

BACKGROUND/AIMS: To describe the role of MDCT-volumetry to monitor and predict liver hypertrophy in a recently introduced surgical technique in patients needing hepatectomy. METHODOLOGY: This prospective study was approved by the local research and ethics committee and patient informed consent was obtained. Twelve consecutive patients were selected for associating liver partition and portal vein ligation for staged-hepatectomy procedure. The mean absolute the future-liver-remnant (FLR) and FLR/total liver volume (TLV) ratio was calculated before and after surgery to determine the degree of hypertrophy. Six days after surgery a new CT-examination was performed to determine the FLR-volume and FLR/TLV. If the enlargement of the FLR was the expected a second-step surgery was performed. Continuous variables are expressed as mean (range). A p<0.05 was considered significant. RESULTS: The mean pre-operative FLR-volume was 402 mL and the FLR/TLV was 27%. The mean post-operative FLR-volume 6 days after the first step was 702 mL (range 521-1030 mL) being the mean difference between preoperative and postoperative FLR volume 303 mL (p<0.0001). The mean volume increase was 80% ranged from 21-139%. At day six, FLR/TLV was 46.5% (range 33.5-67.7), morbidity was 41% and mortality 0%. CONCLUSIONS: MDCT-volumetry has a key role in decision-making, monitoring and predicting liver hypertrophy pre- and postoperatively.

[Robotic total mesorectal excision for rectal cancer]. / Resección total de mesorrecto robótica por cáncer de recto.

Laparoscopic total mesorectal excision (TME) has proven to be feasible and safe. However, it represents a major technical challenge, since it involves the dissection of the rectum in a confined space such as the bony pelvis using un-ergonomic surgical devices. This difficulty is accentuated in patients with distal tumors and high body mass index (BMI), in which the surgical margins and the hypogastric nerves may be affected. Therefore, robotic surgery aims to overcome these limitations that conspire against the mininvasive surgical approach of rectal cancer. We present an obese (BMI = 32 kg/m2) 82-year-old man with a history of smoking and prostate cancer that was recently diagnosed with a middle rectal adenocarcinoma at 9 cm from the anal verge. Rectal examination evidenced a mobile lesion. Computed tomography scan ruled out metastases and at the local staging by MRI, the tumor was considered as T3-N0 with free circumferential margins. Surgical treatment was decided and a hybrid technique was used combining an initial laparoscopic approach followed by the robotic TME. The patient had a full recovery and was discharged three days after surgery without complications. Pathological examination revealed a low-grade adenocarcinoma with mesorectal invasion, free circumferential and distal margins, and 24 negative lymph nodes (pT3-pN0-pM0/Stage II). Robotic TME was performed safely in an obese patient. It facilitated dissection maneuvers in a confined space with proper identification and preservation of the hypogastric nerves, allowing retrieving an intact mesorectum. Prospective randomized trials will define the role of this new technology.

Groove pancreatitis vs groove pancreatic adenocarcinoma. Report of two cases and review of the literature.

Groove pancreatitis (GP) is a rare form of segmental chronic pancreatitis affecting the groove area (anatomic space between the head of the pancreas, the duodenum and the common bile duct). Its clinical and radiological presentation may be similar to groove pancreatic adenocarcinoma (GPA). Nevertheless, treatment and prognosis are totally different. We report two cases of both GP and GPA and review the relevant aspects that may help to clarify the differential diagnosis between these two rare entities. The first patient is a 57-year-old man with a history of chronic alcohol consumption who presented with persistent abdominal pain. The CT-scan findings suggested GP. Due to the persistence of symptoms despite medical treatment, a pancreaticoduodenectomy was performed. Pathologic evaluation confirmed the diagnosis of GP. The second patient is a 72-year-old male who presented with cholestasis and weight loss. The tumor marker CA 19-9 was increased The CT-scan findings were consistent with duodenal dystrophy. In order to rule out malignancy a pancreaticoduodenectomy was performed. Pathologic evaluation revealed a pancreatic head adenocarcinoma (T3-N1-M0). GP is a rare entity that should be suspected in patients with a history of heavy alcohol consumption who complain of chronic abdominal pain and weight loss. Patients without a clear diagnosis even after a through imaging work-up, or those in whom symptoms are persistent in spite of medical therapy, should undergo surgical exploration.

Atlantic Oceanic Squids in the "Grey Speciation Zone".

Cryptic species complexes represent an important challenge for the adequate characterization of Earth's biodiversity. Oceanic organisms tend to have greater unrecognized cryptic biodiversity since the marine realm was often considered to lack hard barriers to genetic exchange. Here, we tested the effect of several Atlantic and Mediterranean oceanic barriers on 16 morphospecies of oceanic squids of the orders Oegopsida and Bathyteuthida using three mitochondrial and one nuclear molecular marker and five species delimitation methods. Number of species recognized within each morphospecies differed among different markers and analyses, but we found strong evidence of cryptic biodiversity in at least four of the studied species (Chtenopteryx sicula, Chtenopteryx canariensis, Ancistrocheirus lesueurii, and Galiteuthis armata). There were highly geographically structured units within Helicocranchia navossae that could either represent recently diverged species or population structure. Although the species studied here can be considered relatively passive with respect to oceanic currents, cryptic speciation patterns showed few signs of being related to oceanic currents. We hypothesize that the bathymetry of the egg masses and duration of the paralarval stage might influence the geographic distribution of oceanic squids. Because the results of different markers and different species delimitation methods are inconsistent and because molecular data encompassing broad geographic sampling areas for oceanic squids are scarce and finding morphological diagnostic characters for early life stages is difficult, it is challenging to assess the species boundaries for many of these species. Thus, we consider many to be in the "grey speciation zone." As many oceanic squids have cosmopolitan distributions, new studies combining genomic and morphological information from specimens collected worldwide are needed to correctly assess the actual oceanic squid biodiversity.