Shell Identification

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AI in Integrative Taxonomy: Mollusk Species Identification with Deep Learning

Published on: 10 March 2024

Abstract

Integrative taxonomy incorporates multiple data sources—morphology, genetics, and ecology—to improve species delimitation. However, challenges such as subjective interpretation and inconsistent species concepts persist. Artificial intelligence (AI), particularly deep learning, has emerged as a transformative tool for automating species identification. Convolutional neural networks (CNNs) can learn distinguishing features directly from images, reducing human bias and enhancing classification accuracy. Studies have demonstrated CNN-based models achieving expert-level performance in mollusk identification, with applications in research, conservation, and industry.
Hybrid AI approaches, integrating deep learning with traditional machine learning techniques like random forests and support vector machines, further refine classification. Unsupervised methods, including clustering algorithms and self-organizing maps (SOMs), allow species discovery without predefined labels. These innovations are revolutionizing taxonomy by accelerating identification workflows and supporting biodiversity research.
Despite these advancements, challenges remain. High-quality training data are essential for model accuracy, and AI struggles with cryptic species that require genetic validation. Variability in field conditions and model interpretability pose additional concerns. Future developments in multimodal AI—integrating images, DNA, and environmental data—promise enhanced accuracy and reliability.
AI-driven taxonomy is evolving into an indispensable tool for taxonomists. By streamlining species identification, it enables experts to focus on analytical and evolutionary insights rather than routine classification. As AI continues to integrate into taxonomic workflows, it holds the potential to significantly advance our understanding of biodiversity, particularly in mollusks.

Introduction

Integrative taxonomy combines multiple data sources (morphology, genetics, ecology, etc.) to more robustly delimit species. However, this approach faces challenges such as inconsistent species concepts, lack of universal diagnostic markers, and subjective interpretation when merging datasets [1]. In recent years, artificial intelligence (AI) – especially deep learning – has been explored as a way to address these issues by learning complex species patterns directly from data. The idea is that AI can automate feature extraction and reduce human subjectivity in species identification [1], potentially accelerating the discovery and description of biodiversity.

AI Approaches in Mollusk Species Identification

AI techniques have shown significant promise in identifying mollusk species from morphological data (e.g. images of shells or body parts). Convolutional neural networks (CNNs) are especially popular for image-based classification tasks and have been applied to mollusk taxonomy (identifyshell.org). For example, deep learning models have been trained to recognize shell images and distinguish between similar species with accuracy rivaling expert identification. For example, CNN models were developed (including VGG, Inception-ResNet, and SqueezeNet) to classify three look-alike ark shell species from images [2]. Noshaba Qasmi et al .[3] used Conus images to create an AI model. This study used a deep CNN (VGG16) to extract image features from 47,600 shell photographs, then classified species with an ensemble of machine learning algorithms (CNN for feature extraction + Random Forest classifier). A high accuracy (95.8% accuracy), attained on a large dataset, suggests AI can handle fine-grained species discrimination even among cryptic shell patterns [3]. A similar study was made by the dutch organization Naturalis [4]

While CNN-based image recognition is a dominant approach, other AI models are also used in taxonomy. Traditional machine learning classifiers like random forests and support vector machines (SVMs) have been combined with deep learning in a complementary way. In the cone snail example above, the CNN acted as an automated feature extractor, and a Random Forest and XGBoost ensemble then performed the final classification [3]. These examples show that AI in taxonomy is not limited to pure deep neural networks – it often involves hybrid pipelines where deep learning provides powerful features and other algorithms handle classification or clustering. Unsupervised AI methods are also emerging for taxonomy; for instance, clustering algorithms and self-organizing maps can group individuals into potential species without prior labels, which is useful for discovering new or cryptic species. [5, 6, 7]

Automating Feature Extraction with CNNs

Traditional taxonomic research often relies on experts to discern and measure morphological traits for distinguishing species. This process can be time-consuming and subjective, as different taxonomists might emphasize different features or interpretations ​[10]. For example, identifying a mollusk species by shell shape or pattern traditionally requires an expert’s judgment on which traits (e.g. shell curvature, coloration, rib patterns) are diagnostically important. Recent advances in artificial intelligence (AI), especially convolutional neural networks (CNNs), offer a way to reduce this subjectivity by automating feature extraction. Instead of pre-defining traits, CNN models learn relevant features directly from raw data (images, sounds, DNA sequences, etc.), potentially capturing subtle characteristics that experts might overlook or not think to measure [11]. CNNs mimic aspects of the human visual system, processing images through layers that detect increasingly complex patterns. Early layers might detect simple shapes or textures (edges, spots), while deeper layers capture higher-level structures (like the outline of a wing or the spiral of a shell). Crucially, CNNs do this without explicit instruction on which features to look for. In classical approaches, researchers had to handcraft features (e.g. ratios of body parts, counts of spines, color metrics), which was labor-intensive and could embed human bias. In contrast, deep CNNs “learn to extract relevant features automatically, without human intervention” from training images ​[11, 12]. In the context of taxonomy, this means the network autonomously figures out what visual cues distinguish one species from another. Studies have shown that CNNs can uncover the same kinds of diagnostic characters that taxonomists use – and sometimes additional ones. For instance, a deep learning model trained on fossil shell images extracted features such as shell ribbing, aperture shape, and growth line patterns that align with traditional morphological criteria, despite not being told explicitly to measure those ​[10, 11]. The model’s internal feature representations effectively created a “morphological feature space” separating taxa: when visualized (e.g. via t-SNE dimensionality reduction), the network’s learned features clearly clustered images by species and even higher groups ​[12]. Note that an hierarchical CNN framework that mirrors the taxonomy as for example defined in WoRMS is ideally suited to extract features on many taxonomic levels (Hierarchical CNN to identify Mollusca). This demonstrates that CNNs can quantify morphology objectively – the network considers all visual information in the image, not just a few traits an expert deems important​.

Another advantage is efficiency: CNNs handle high-dimensional data and large specimen sets that would overwhelm manual analysis. They can capture minute differences – for example, subtle texture variations on insect elytra or slight curvature differences in shells – across thousands of images, distilling consistent patterns that define each species​ ​[12]. This capability is akin to an expert examining countless specimens and mentally noting diagnostic nuances, but the CNN does it quantitatively and reproducibly. In a study of mollusk fossils, the CNN’s extracted features were so informative that it could separate two molluscan classes (bivalves vs. brachiopods) purely from images, matching the expert-defined class boundaries without being told those labels beforehand​.

Practical Applications of AI-Driven Taxonomy

AI-based taxonomy tools for mollusks are moving from research into practical use. One major application is in automated species identification systems that can assist non-experts (identifyshell.org) or speed up workflow for taxonomists. For example, a deep learning system for classifying marine bivalves in the Philippines was incorporated into a smartphone app, allowing users to identify threatened shellfish species on-site [8]. In the seafood and aquaculture industry, AI identification can improve efficiency and food safety. The ark shell classifier mentioned earlier [2] was motivated by the need to rapidly sort large catches of similar-looking clams. A reliable model that runs on standard hardware (or a phone) can process images of shells in seconds, far faster than manual inspection. Likewise, museums and research collections stand to gain from AI by bulk-processing specimen images to either identify them or flag potential new species [4]. AI can sift through thousands of shell photographs and cluster them by similarity, highlighting outliers that may merit closer taxonomic examination. In ecological monitoring, automated camera systems could use trained models to log mollusk species presence on shorelines or reefs, supporting biodiversity surveys with minimal human labor.

Limitations and Challenges

Despite their promise, AI models in taxonomy come with limitations. A primary challenge is the need for high-quality training data. Deep learning models require many images per species to learn distinguishing features reliably [ Identifying Shells using Convolutional Neural Networks: Data Collection and Model Selection]. For rare or newly discovered mollusks, we may not have enough photos or specimens available. Data collection can be biased too – if all training images show shells on a uniform background, the model may falter on photos taken in natural habitats (different lighting, angles, or with the animal alive). Ensuring that models generalize to real-world conditions requires carefully curated, diverse datasets. Some studies have noted that AI classifiers often excel on curated image sets but might struggle when faced with field photos outside the original training distribution [9]. This means additional work is needed to make models robust under variable conditions (e.g. by augmenting training data or using domain adaptation techniques).

Another limitation is that morphological AI alone cannot resolve all taxonomic problems. Many mollusk species complexes are cryptic, meaning they are nearly indistinguishable in appearance but separable by genetics or other data. A CNN can only use the visual cues available – if two species are identical-looking, no amount of training will allow the model to tell them apart from images. In such cases, integrative taxonomy relies on DNA sequencing, behavior, or ecology. AI can assist here by integrating those data layers (for example, clustering individuals by genetic patterns), but this is more complex than a straightforward image classification. There’s progress in that direction: new machine learning methods can combine genetic, geographic, and morphological inputs to propose species boundaries [7]. Still, these approaches are in early stages, and interpreting their output in a taxonomic context (deciding if a cluster is truly a distinct species) requires expert judgment. In practice, AI suggestions must be validated by taxonomists, especially for describing new species.

Wrong prediction without a clear reason can erode confidence in the tool. Moreover, AI models might latch onto irrelevant features or errors in the training data. If misidentified specimens are included in training sets, the model can learn false patterns. Quality control in the training phase is therefore critical in a scientific context. Finally, there are technical limitations: training deep networks is computationally intensive and may be inaccessible to smaller institutions without specialized hardware or expertise. Fortunately, once a model is trained, deploying it (even on a smartphone) is much easier, but the upfront resource investment can be a barrier.

Future Perspectives

AI-driven integrative taxonomy is a fast-evolving field, and future developments could greatly enhance how we document molluscan diversity. One promising direction is multimodal AI – systems that simultaneously analyze multiple types of data. Instead of handling images or DNA sequences in isolation, future models might take in a shell photo, the specimen’s DNA barcode, its collection location, and even environmental parameters, and then output a probable species identification or delimitation [1]. Research in unsupervised machine learning is laying the groundwork for this: recent work introduced Self-Organizing Maps (SOMs) that combine genetics, geography, climate, and morphology into a single analytical framework for species delimitation [7]. While demonstrated on salamanders and snakes, this integrative clustering approach could be applied to mollusks (for instance, delimiting closely related snail species by simultaneously considering shell shape variation, genetic divergence, and habitat differences). Such AI tools might eventually support taxonomists by objectively suggesting species boundaries that reconcile disparate data sources.

In terms of practical taxonomy, we can expect AI to become a standard assistive tool. Future taxonomists might routinely use AI-based apps or software to pre-screen specimens. For example, an ecologist surveying a reef could photograph mollusks and have an app instantly list likely species, with confidence scores. This doesn’t remove the expert from the loop but streamlines the process, focusing expert attention on cases where the AI is uncertain or flags a potential novelty. As more training data become available (through digitization of museum collections and crowdsourced observations), AI models will continue to improve in accuracy and scope. We may see global platforms that can identify any common mollusk species from a photo, similar to how birders use Merlin or other AI-powered guides for bird identification. There is also interest in explainable AI for taxonomy – incorporating mechanisms that highlight distinguishing features on an image (e.g. the banding pattern on a shell the model used to decide) so that the AI effectively teaches the user what to look for. This could be invaluable for training new taxonomists and citizen scientists, turning AI from a mysterious oracle into a educational tool.

Finally, AI might contribute to the acceleration of new species discovery and description. With millions of undescribed species globally and a limited number of taxonomists, automation can help triage the workload. In mollusks, shell image classifiers could quickly scan through years of collector photographs or remote camera footage to spot specimens that “don’t fit” known categories, hinting at undocumented species. Combined with integrative analyses (like DNA comparison), this could speed up the formal description process. Karbstein et al. [1] have suggested that integrative taxonomy coupled with AI under a unified species concept will reduce subjectivity and accelerate the cataloguing of eukaryotic biodiversity. In essence, the future may hold an era of “augmented taxonomists” – professionals who leverage powerful AI assistants to handle the tedious aspects of sorting and identification, while they focus on the synthesis, nomenclature, and deeper biological insights. Such a synergy between AI and human expertise will be key to fully realizing AI’s potential in integrative taxonomy.

Conclusion

AI techniques – from convolutional neural networks to ensemble classifiers and clustering algorithms – are proving to be valuable tools in integrative taxonomy, especially for mollusk species identification. They offer high speed and accuracy in recognizing species from images and can integrate multiple data types to tackle complex taxonomic problems. Practical deployments are already emerging in fields like conservation, fisheries, and biodiversity research. Nonetheless, challenges such as data requirements, model generalization, and interpretability must be managed carefully. AI is not a wholesale replacement for human taxonomic expertise, but rather a powerful complement to it. By handling large data and routine identifications, AI frees up taxonomists to concentrate on analysis and decision-making. Looking ahead, deeper integration of AI with taxonomic workflows and data sources promises a more efficient and objective taxonomy, ultimately supporting better understanding and preservation of molluscan diversity and life on Earth.

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